Exclaimer Outage History

Started Oct 06, 2026, 12:17 PM UTC· resolved Oct 06, 2026, 03:43 PM UTC

1. investigating Oct 06, 2026, 12:17 PM UTC

   Exclaimer Engineers are aware of a possible issue that is preventing some subscriptions from accessing the Exclaimer Portal. The cause is currently being investigated, and more information will be shared shortly.

2. identified Oct 06, 2026, 12:40 PM UTC

   Exclaimer Engineers are taking action to restore the service to full operation at this time. We have been able to confirm that signatures being applied through Client-side and Server-side methods are continuing to apply as expected.

3. monitoring Oct 06, 2026, 12:57 PM UTC

   We've restored access to the Exclaimer admin portal and management pages for the UAE region by redirecting traffic to our secondary UAE infrastructure. Our checks show the pages loading normally again. We're continuing to monitor while we investigate the underlying cause. Email signature delivery wasn't affected. We'll post another update when we have more information.

4. monitoring Oct 06, 2026, 03:02 PM UTC

   The cause of the issue has been identified, and mitigation has been applied to restore full access to the User Interface for impacted customers.

5. resolved Oct 06, 2026, 03:43 PM UTC

   Exclaimer Engineers have confirmed that the incident has been resolved. The issue was caused by a Cloudflare incident (https://www.cloudflarestatus.com/incidents/ryvhi2suec0d) affecting connectivity between Cloudflare and Azure that prevented routing traffic to one of our available UAE Datacenters, which remained healthy throughout. Exclaimer Engineers worked around the issue by routing traffic away from the impacted route until Cloudflare had resolved the issue and all traffic is now routing as normal following testing and a period of extended monitoring. If you have any questions or concerns, please reach out to our great support team, who will be more than happy to help answer any questions.

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Started Sep 22, 2026, 10:58 AM UTC· resolved Oct 09, 2026, 08:40 AM UTC

1. investigating Sep 22, 2026, 10:58 AM UTC

   Exclaimer engineers are investigating a delivery delay affecting some messages sent from Outlook and Exchange to Exclaimer Cloud. Some of these messages may be retried by the sender and may appear as temporary deferrals rather than delivery failures. We are not currently aware of any confirmed message loss and will provide updates as we learn more.

2. identified Sep 22, 2026, 03:19 PM UTC

   Exclaimer has identified that a small subset of messages (~0.02%) are delayed when routed through Exclaimer due to a suspected issue within Microsoft's servers. This has been raised with Microsoft to investigate alongside Exclaimer Engineers. Sent messages will be received with a signature applied, as expected. If you are seeing issues with message deliverability, please reach out to our support team, who will be happy to assist.

3. monitoring Sep 27, 2026, 07:33 PM UTC

   Mail delivery has resumed as normal and our engineers are seeing significantly less errors. The team are awaiting confirmation of a fix implemented on Microsoft servers and will be monitoring until tomorrow morning to confirm.

4. resolved Oct 09, 2026, 08:40 AM UTC

   The original impact of the issue has been mitigated by Microsoft changes. Exclaimer Engineers are continuing to work together with Microsoft to establish a root cause. If you have any questions or concerns, please reach out to our great support team, who will be more than happy to help answer any questions.

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Started Sep 22, 2026, 10:08 AM UTC· resolved Sep 23, 2026, 07:58 AM UTC

1. investigating Sep 22, 2026, 10:08 AM UTC

   Exclaimer engineers are investigating a delivery delay affecting some messages sent from Gmail/Google Workspace to Exclaimer Cloud. Some of these messages may be retried by the sender and may appear as temporary deferrals rather than delivery failures. We are not currently aware of any confirmed message loss and will provide updates as we learn more.

2. investigating Sep 22, 2026, 10:15 AM UTC

   We are continuing to investigate this issue.

3. monitoring Sep 22, 2026, 03:58 PM UTC

   Our engineers have confirmed this issue was caused by a change on Google's side, that we have implemented a code change to mitigate and will continue to work with Google to address the issue.

4. resolved Sep 23, 2026, 07:58 AM UTC

   This incident has been resolved.

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Started Sep 08, 2026, 03:02 PM UTC· resolved Sep 08, 2026, 03:54 PM UTC

1. monitoring Sep 08, 2026, 03:02 PM UTC

   Engineers have applied a mitigation for the issue affecting mail processing that began at 14:37 UTC. Some messages experienced delays while imprinting was retried, and a small number of messages may have been sent without a signature applied. Our engineering team is continuing to monitor performance to confirm full recovery.

2. resolved Sep 08, 2026, 03:54 PM UTC

   Email signature delivery is operating normally in the US again after mitigation by engineers. Between 14:20 and 14:54 UTC, customers may have experienced some minor delays whilst imprinting was retried internally and a small number of messages may have been delivered without a signature applied. We apologise for any disruption caused.

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Started Aug 27, 2026, 10:14 AM UTC· resolved Aug 28, 2026, 08:35 AM UTC

1. identified Aug 27, 2026, 10:14 AM UTC

   Exclaimer support staff are currently addressing an issue that is affecting the delivery of email responses from our support team. If you have an ongoing support ticket, you can log in to the support portal to check for any potential updates and reply to the support engineer assigned to your case. You can access your current tickets and respond to the assigned Support Engineer by following the steps outlined in this guide: https://support.exclaimer.com/hc/en-gb/articles/9389259466141

2. resolved Aug 28, 2026, 08:35 AM UTC

   Exclaimer staff have made an internal change, and monitoring indicates that the issue has now been completely resolved. If you have an open ticket with our support team and have not received a response this week, please follow up on your case via email or directly through our web portal. To access your current tickets and reply to our support team, please follow the steps provided in this guide: https://support.exclaimer.com/hc/en-gb/articles/9389259466141.

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Started Aug 20, 2026, 12:34 PM UTC· resolved Aug 20, 2026, 04:08 PM UTC

1. investigating Aug 20, 2026, 12:34 PM UTC

   Engineers are aware of an issue affecting the Signature Designer, which is preventing some customers from editing signature templates. There is no impact to mail flow or signature delivery at this time. We are investigating and will provide a further update within 60 minutes.

2. monitoring Aug 20, 2026, 12:59 PM UTC

   Exclaimer engineers have resolved the issue, and customers should no longer experience any issues when using the Signature Designer. We are now monitoring for any further issues.

3. resolved Aug 20, 2026, 04:08 PM UTC

   Engineers have confirmed that the previous service alert has been resolved. The service is now back to full health and is working as normal. Thank you for your patience.

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Started Aug 18, 2026, 08:31 AM UTC· resolved Aug 19, 2026, 08:20 AM UTC

1. investigating Aug 18, 2026, 08:31 AM UTC

   Exclaimer Engineers are aware of a transient issue that may cause certain pages, such as Branding, Campaigns, and Disclaimers, to fail to load for customers within the Exclaimer Portal. Remediation work is underway to restore access to these sections of the portal. Signatures are still being applied to Emails. If you are seeing that signatures are not being applied, please contact our support team, who will be happy to help.

2. monitoring Aug 18, 2026, 10:39 AM UTC

   Our engineers have resolved the issue, and customers should no longer experience any issues when using the Exclaimer Cloud Portal. We are now monitoring to ensure stability remains. If you are continuing to see issues, please don't hesitate to contact our support team, who will be happy to help.

3. monitoring Aug 18, 2026, 12:23 PM UTC

   Exclaimer Engineers are aware of reports of the Signature Designer failing to load for some customers. Initial remediation actions have been taken, and the Signature Designer should now load as expected for users. We are investigating the cause of the issue now

4. identified Aug 18, 2026, 01:21 PM UTC

   We have identified an issue within the portal where some buttons are not responding to clicks for some users. Engineers are working now to resolve the issue.

5. monitoring Aug 18, 2026, 02:21 PM UTC

   Engineers have been able to resolve the issue and have resumed monitoring for any further issues.

6. resolved Aug 19, 2026, 08:20 AM UTC

   Our engineers have monitored over the evening and confirmed this is now resolved

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Started Aug 08, 2026, 11:08 AM UTC· resolved Aug 08, 2026, 03:00 PM UTC

1. investigating Aug 08, 2026, 11:08 AM UTC

   We are currently investigaing an issue with Data sync in the UK

2. investigating Aug 08, 2026, 11:15 AM UTC

   This appears to be more widespread than firs thought.

3. identified Aug 08, 2026, 12:28 PM UTC

   Exclaimer Engineers have identified the cause of the error, and initial attempts to remediate the issue have not been successful at this time. The team is continuing to work to resolve the error. User data that has been synchronized to Exclaimer previously will continue to be displayed as expected. Another update will be provided within the next hour.

4. identified Aug 08, 2026, 01:08 PM UTC

   Engineers have been able to identify and confirm a fix and are implementing it in all impacted regions now.

5. monitoring Aug 08, 2026, 01:34 PM UTC

   Exclaimer engineers have now applied the fix to all impacted regions and have confirmed that data is synchronizing as expected for subscriptions. We are now continuing to monitor for any unexpected issues.

6. resolved Aug 08, 2026, 03:00 PM UTC

   No further signs or unexpected errors have occurred since the remediation action was taken, and user data is now synchronising to Exclaimer as expected. If you are seeing issues with user information not appearing within Exclaimer as expected, please attempt to manually synchronise user data from within the Exclaimer Portal.

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Started Aug 04, 2026, 07:14 PM UTC· resolved Aug 05, 2026, 06:34 AM UTC

1. investigating Aug 04, 2026, 07:14 PM UTC

   We are currently seeing an increase in imprint failures for messages processed in the US1 datacenter.

2. identified Aug 04, 2026, 07:38 PM UTC

   We have identified an issue with the auto scaling on key services. These have been manually scaled and we are seeing recovery.

3. monitoring Aug 04, 2026, 07:54 PM UTC

   Imprinting has now recovered and is operationsl once more. Engineers will continue to monitor the situation.

4. resolved Aug 05, 2026, 06:34 AM UTC

   This incident has been resolved.

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Started Jul 31, 2026, 12:59 PM UTC· resolved Aug 03, 2026, 07:21 AM UTC

1. investigating Jul 31, 2026, 12:59 PM UTC

   Exclaimer Engineers are investigating a potential mail flow delivery issue within the US region at this time. Preventive action has been taken to mitigate the issue, and more information will be provided when possible.

2. monitoring Jul 31, 2026, 01:26 PM UTC

   The applied preventive messages have effectively stabilized the potential delay. Engineers are continuing to monitor for any signs of further issues.

3. resolved Aug 03, 2026, 07:21 AM UTC

   Our engineers monitored over the weekend and mail flow as been progressing as normal.

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Started Jul 25, 2026, 10:07 PM UTC· resolved Jul 26, 2026, 03:24 PM UTC

1. investigating Jul 25, 2026, 10:07 PM UTC

   We are currently investigating recurring instability affecting our US region Postgres database infrastructure. This is caused by an underlying Azure infrastructure issue (Tracking ID: SRV7-K0G). Some US customers may experience intermittent issues with Active Directory sync and the admin user interface during this window. We are working with Microsoft Azure to resolve this as quickly as possible. We will provide updates every 30 minutes. Started: 25 Jul 2026, 22:20 BST

2. investigating Jul 25, 2026, 10:10 PM UTC

   We are continuing to investigate this issue.

3. identified Jul 26, 2026, 12:09 AM UTC

   The issue has been identified and a fix is being implemented. Email delivery and signature application are not affected and continue to operate normally. Following the previous incident in US on July 24th one of the database replicas did not recover normally after the outage was resolved, and because of this storage was quickly used up on the primary database server. Recovery is in progress and replication is catching up slowly, we expect this to take course over the course of Sunday. The impacts noted still apply as we have temporarily paused data synchronisation attempts (including SCIM and HRIS) in order to complete recovery. We will provide the next update within 12 hours.

4. monitoring Jul 26, 2026, 09:15 AM UTC

   Update - 26 Jul 2026, 10:15 BST Database recovery has completed overnight ahead of schedule. Storage has returned to normal levels and replication is fully caught up. We are currently in the process of re-enabling paused services. We will update the affected components to Operational once services have been fully restored. Email delivery and signature application continue to operate normally.

5. resolved Jul 26, 2026, 03:24 PM UTC

   Update - 26 Jul 2026, 16:25 BST All services have been fully restored. Database storage and replication are healthy. Data synchronisation (SCIM, HRIS) has resumed normally. No customer data was lost. We apologise for any inconvenience caused.

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Started Jul 23, 2026, 03:32 PM UTC· resolved Jul 24, 2026, 08:45 AM UTC

1. investigating Jul 23, 2026, 03:32 PM UTC

   We are currently experiencing issues with email signature delivery for customers in the US region due to an underlying Azure infrastructure issue in West US. Emails are being delivered but signatures may not be applied during this window. We are actively working to restore full service and will provide updates every 30 minutes.

2. investigating Jul 23, 2026, 03:35 PM UTC

   We are continuing to investigate this issue.

3. investigating Jul 23, 2026, 04:28 PM UTC

   Update - 23 Jul 2026, 17:20 BST We continue to investigate an issue affecting email signature delivery for customers in the US region, caused by an external Azure infrastructure issue in West US. Email is still being delivered. Signatures may intermittently not be applied during this window. We have scaled our US infrastructure and are actively working to restore full service.

4. investigating Jul 23, 2026, 05:19 PM UTC

   Update - 23 Jul 2026, 18:15 BST We have restored email signature delivery for customers in the US region. Emails are now being delivered with signatures applied. We are continuing to monitor the situation while Microsoft investigate the underlying Azure West US infrastructure issue. We will provide a further update if any impact is detected. We apologise for any inconvenience caused.

5. monitoring Jul 23, 2026, 05:20 PM UTC

   A fix has been implemented and we are monitoring the results.

6. monitoring Jul 23, 2026, 08:06 PM UTC

   Email signature delivery has been restored for customers in the US region. While the underlying issue was with Azure's West US infrastructure, we made adjustments to our systems to mitigate the impact and maintain service during the outage. We are continuing to monitor the situation. Please contact support if you experience any further issues. We apologise for any inconvenience caused.

7. resolved Jul 24, 2026, 08:45 AM UTC

   Update - 24 Jul 2026, 09:30 BST All services have been fully restored across the US region. Email signature delivery is operating normally in both US datacenters following the Azure West US infrastructure outage on 23 July 2026. We apologise for any disruption caused.

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Started Jul 10, 2026, 11:03 AM UTC· resolved Jul 10, 2026, 03:52 PM UTC

1. investigating Jul 10, 2026, 11:03 AM UTC

   Exclaimer Engineers are investigating an issue where some customers may receive an 'unexpected error occurred' page when attempting to navigate to the Signatures, Campaigns, or Disclaimers tabs. If you are experiencing this issue, please raise a support ticket using the link below. https://support.exclaimer.com/hc/en-gb/p/raise-ticket Signatures are continuing to be applied as expected to messages through both the mail flow rule and the Exclaimer add-in.

2. identified Jul 10, 2026, 02:39 PM UTC

   Exclaimer Engineers have identified the cause of the issue and are implementing changes to address the cause. We have also verified that this issue affected a small subset of customers.

3. resolved Jul 10, 2026, 03:52 PM UTC

   A successful change has addressed the issue, including mitigation to prevent the issue from occurring again. Customers should no longer see any error messages or encounter any issues when accessing the Signatures, Campaigns, or Disclaimers tabs. If you are experiencing any issues with the Exclaimer Portal, please raise a support ticket, and our team will be happy to help https://support.exclaimer.com/hc/en-gb/p/raise-ticket

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Started Jul 01, 2026, 11:45 AM UTC· resolved Jul 01, 2026, 03:41 PM UTC

1. identified Jul 01, 2026, 11:45 AM UTC

   Exclaimer engineers are aware of an issue where messages within the UK may be impacted and fail to be delivered at this time. The team is actively working to address the issue

2. monitoring Jul 01, 2026, 12:10 PM UTC

   Exclaimer engineers have applied a fix to address the issue, ensuring no further messages will be affected. Any messages that were impacted would have been deferred for delivery and would be sent rather than failing to be delivered entirely. We will continue to monitor and provide further updates in the next hour.

3. resolved Jul 01, 2026, 03:41 PM UTC

   The issue is now resolved and the all mail flow processing is operational

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Started Jun 29, 2026, 07:35 AM UTC· resolved Jun 29, 2026, 08:51 AM UTC

1. investigating Jun 29, 2026, 07:35 AM UTC

   We were alerted to an issue with mail flow in our primary data centers. Our engineers are currently investigating and trying to resolve asap

2. identified Jun 29, 2026, 08:00 AM UTC

   Our engineers have identified the issue and are mitigating. Customers may still experience delays in mail delivery

3. monitoring Jun 29, 2026, 08:26 AM UTC

   We have mitigated the issue and mail flow is working again in all regions. We are monitoring now to ensure this has resolved the issue.

4. resolved Jun 29, 2026, 08:51 AM UTC

   The incident has been resolved by our engineers and mail routing is operational across all regions. Customers may have experience mail delivery delays but these would have been delivered following retries.

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Started Jun 25, 2026, 04:48 PM UTC· resolved Jun 30, 2026, 02:53 PM UTC

1. identified Jun 25, 2026, 04:48 PM UTC

   Exclaimer is aware of an issue that may cause problems when attempting to purchase and set up Exclaimer Cloud via the Microsoft Marketplace at this time. Starting a Trial, or purchasing through an authorized reseller or directly from Exclaimer, is working as expected. More information will be provided once it is available.

2. resolved Jun 30, 2026, 02:53 PM UTC

   Customers are now able to purchase and set up via Microsoft marketplace again. There was a latent configuration issue within our Microsoft tenant that only became a problem recently. We are still investigating what changed Microsoft side that lead to this becoming an issue.

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Started Jun 23, 2026, 04:33 PM UTC· resolved Jul 07, 2026, 10:41 AM UTC

1. identified Jun 23, 2026, 04:33 PM UTC

   Customers in the AU and US may experience issues with emails being quarantined by Microsoft defender due to false positive phishing detection. Our engineers are working with Microsoft to have the domain reputation cleared as soon as possible.

2. identified Jun 24, 2026, 12:51 PM UTC

   Our engineers have escalated the urgency of this with Microsoft and continue to push for updates as soon as possible.

3. identified Jun 29, 2026, 12:11 PM UTC

   Our engineers are continuing to engage with Microsoft regarding this issue and escalating to highest priority. This is only affecting mail flow of customers that are using the Engagement analytics feature. Please contact us to support unblocking your emails as necessary.

4. monitoring Jul 01, 2026, 10:13 AM UTC

   Exclaimer Engineers, in cooperation with Microsoft, have been able to update their detection system to prevent our analytic links from being incorrectly identified as phishing. This change should complete replication through Microsoft 365 over the next 24 hours. Customers who have disabled analytics within the Exclaimer Portal can look to enable the Analytics feature within the Exclaimer Portal or contact Exclaimer Support for assistance if needed. We will provide another update tomorrow or when more information is available.

5. resolved Jul 07, 2026, 10:41 AM UTC

   After extended monitoring, Exclaimer engineers are no longer seeing any continued instances of click-tracking links within the impacted regions being flagged by Microsoft Defender at this time. Customers who previously disabled this feature can look to enable click-tracking analytics from within the Exclaimer Cloud portal. If you are continuing to see issues, please don't hesitate to reach out to our support team, who will be able to assist.

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Started Jun 22, 2026, 07:01 PM UTC· resolved Jun 23, 2026, 08:01 AM UTC

1. investigating Jun 22, 2026, 07:01 PM UTC

   Exclaimer engineers are aware of an issue causing some images not to appear within the signature tester result when a test is run. The same images appear as expected in the signature designer and in live messages. There is no impact on email signatures, as these images are applied as expected.

2. resolved Jun 23, 2026, 08:01 AM UTC

   This incident has been resolved. Web-hosted images in the signature editor are now loading correctly across all regions. A recent update to the cloud UI's Content Security Policy inadvertently restricted external image sources, causing hosted images to fail to display. The policy has been updated to allow the required image sources, and the fix has been deployed to all production regions. We're monitoring to confirm stability. We apologize for any disruption this caused.

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Started Jun 10, 2026, 02:44 PM UTC· resolved Jun 10, 2026, 03:43 PM UTC

1. investigating Jun 10, 2026, 02:45 PM UTC

   Exclaimer Engineers are aware of an issue that may cause messages to be delayed when sent to Exclaimer Cloud for Microsoft 365 users in the UK. More information will be provided once it is available.

2. investigating Jun 10, 2026, 02:52 PM UTC

   Exclaimer Engineers have made a change in the UK region to prevent messages from being delivered to the affected servers. This should prevent further messages from being impacted and ensure that impacted messages are processed as expected on the next attempt.

3. monitoring Jun 10, 2026, 03:02 PM UTC

   Exclaimer Engineers have confirmed that the error rate is now dropping after a spike in both UK regions, suggesting that other actions taken have been able to address the issue. We are continuing to look into the cause whilst monitoring for any further issues.

4. resolved Jun 10, 2026, 03:43 PM UTC

   After continued monitoring, we have confirmed the issue is no longer occurring. Servers that were displaying errors have been removed and replaced within our UK region to prevent the issue from reoccurring. If you are still seeing issues with mail flow when using Exclaimer at this time, please reach out to our support team directly, who will be happy to help.

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Started May 28, 2026, 08:40 AM UTC· resolved May 28, 2026, 01:12 PM UTC

1. identified May 28, 2026, 08:40 AM UTC

   Issue: An Azure storage failure in EU2 is resulting in delays processing messages there, engineering teams are actively mitigating the issue. Symptoms: Some messages processed in EU could be delayed. Next Update In: 30 mins or less

2. monitoring May 28, 2026, 09:03 AM UTC

   Exclaimer Engineers have successfully mitigated the issue and mailflow had returned to normal levels.

3. resolved May 28, 2026, 01:12 PM UTC

   The Azure SQL database in EU2 has been fully restored by Microsoft. EU2 endpoints have been re-enabled and mailflow is balanced. All services are confirmed healthy with no further impact to customers.

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Started May 28, 2026, 08:01 AM UTC· resolved May 29, 2026, 10:47 AM UTC

1. investigating May 28, 2026, 08:01 AM UTC

   Engineers are aware of an issue impacting our ability to apply signatures to messages as they are composed, the message 'Failed to acquire auth token' is displayed. There is no impact to email delivery at this time, once the issue has been resolved signatures will start to be applied again. If you have our server-side offering configured, then you will find that signatures are applied to messages after they are sent. If you have any other issues, please contact our support team who will be happy to help

2. identified May 28, 2026, 12:16 PM UTC

   Our team have identified the issue and are actively working on a resolution. Further updates will follow once a fix has been identified.

3. monitoring May 28, 2026, 02:17 PM UTC

   Engineering has successfully tested and deployed a fix for the add-in to resolve this issue. We will continue to closely monitor the add-in’s performance following the release. Please note that the speed of adoption may vary depending on Outlook cache. If you are currently experiencing any further issues with Exclaimer, please contact our Support team for assistance.

4. monitoring May 28, 2026, 04:04 PM UTC

   We continue to see a reduction of errors as the new version rolls out and are monitoring its progress. Please note that the speed of adoption may vary depending on Outlook cache. If you are currently experiencing any further issues with Exclaimer, please contact our Support team for assistance.

5. resolved May 29, 2026, 10:47 AM UTC

   Microsoft have confirmed that the original issue impacting customers was the result of a server-side change that has since been reverted. Our telemetry also confirms that over 40% of customer requests are coming from the newly released version that similarly resolved customer issues prior to Microsoft's deployment reversal, this continues to roll out. We intend to leave this fix in place as it improves the add-ins resilience to possible authentication issues. If you are currently experiencing any further issues with Exclaimer, please contact our Support team for assistance.

6. postmortem Jun 10, 2026, 05:46 PM UTC

   Issue: Client side signature fails to apply and the message 'Failed to acquire auth token' is displayed. Incident Length: 10 Day\(s\) and 3 hour\(s\) Incident Date: 18/05/2026, 11:00 UTC - 28/05/2026, 14:05 UTC Incident Status: Resolved **Summary** When composing a new email, the Exclaimer add-in was unable to acquire an authentication token, resulting in signatures not being inserted and an error message being displayed for customers using Outlook for iOS. All other platforms, including Windows desktop, New Outlook, Mac, Web, and Android, were unaffected. Server-side signatures continued to apply normally for customers with that configuration. **Root Cause** The Exclaimer Outlook Add-in uses a Microsoft authentication flow designed for Office add-ins, which is intended to authenticate users silently in the background without any user interaction. Around 18 May, this silent authentication flow stopped working on Outlook for iOS. Following an investigation, Microsoft confirmed that a change on their side had caused the silent authentication failure, and that this change was subsequently rolled back. **Mitigation** On identifying where the authentication flow was failing, Exclaimer Engineers updated the Outlook Add-in \(v1.29.200\) to introduce a fallback path for when silent authentication cannot complete. Rather than surfacing an error, the add-in now prompts the user to sign in interactively, allowing authentication to complete and the signature to be applied, improving authentication flow resilience. This was deployed on 28 May and has been retained permanently as a resilience improvement. **Incident Timeline** 18/05, ~11:00 UTC - Silent authentication begins failing on Outlook for iOS. Customers start experiencing signature failures on this platform 18/05, 12:51 – Exclaimer releases a new version of the Exclaimer Add-in \(v1.27.200\) 21/05, 19:01 - First report of errors from the Add-in reaches Exclaimer Engineering. Investigation begins. 22/05, 07:26 Engineering confirmed a review of the latest Add-in release had been completed; no active indicators of the issue are present based on the changes made. 10:14 – Active theory was composed on the cause of the issue; code changes are then prepared by Engineering to be released the following week to prevent potential issues over the weekend. 26/05, 10:01 UTC - First code change deployed to improve logging and extend authentication timeouts. 12:10 – Add-in v.1.28.0 is released to the production channel of the Add-in. Review of impacted systems indicates no improvement. 27/05, 13:25 UTC - v.1.29.0 is deployed to both channels to surface more detail from the authentication failure on iOS. 28/05, 07:44 UTC - Severity escalated given customer impact and duration. 10:42 – Issue confirmed to only impact iOS, with other errors likely being unrelated. 11:03 – Internal investigation is prioritized to identify the cause. 11:30 - Internal reproduction of the issue achieved for the first time, enabling rapid iteration on a fix. 13:02 - The point of failure in the authentication flow fully identified, Exclaimer Engineers also identify development of a Fix and begin prioritizing a full release. 13:50 – Add-in version \(v1.29.200\) is prepared for release, awaiting confirmation of the resolution within the preview channel before being released to the production channel. 14:05 - Updated add-in \(v1.29.200\) verified in preview and released out to production channel. 14:31 - Customer confirmation of resolution is received 29/05, 08:10 UTC - Microsoft confirms that a change on their side caused the authentication failure and that it has been rolled back. Exclaimer Engineers agree to keep the changes applied based on this information at this time.

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Started May 25, 2026, 04:00 AM UTC· resolved May 25, 2026, 10:51 AM UTC

1. investigating May 25, 2026, 04:00 AM UTC

   We are investigating a possible service alert. Issue: Users are unable to receive any authentication tokens when attempting to login to https://portal.exclaimer.com using password login. The issue currently looks to only be affecting users who are logging into the Exclaimer portal using Password login. Logins using Microsoft/Google SSO currently get through without any issues. Symptoms: Users will be prompted to enter a token when trying to login to the portal but no authentication tokens are received in the user's registered email address.

2. investigating May 25, 2026, 08:49 AM UTC

   We are continuing to investigate the issue to determine the root cause. Our IT will report back shortly

3. investigating May 25, 2026, 09:47 AM UTC

   We are still continuing to investigate the issue to determine the root cause. Our IT will report back soon

4. monitoring May 25, 2026, 10:32 AM UTC

   Our engineers have found the issue and reverted a change. Authentication tokens are now being received and we are continuing to monitor.

5. monitoring May 25, 2026, 10:32 AM UTC

   We are continuing to monitor for any further issues.

6. resolved May 25, 2026, 10:51 AM UTC

   Engineers have confirmed that the previous service alert has been resolved. The service is now back to full health and is working as normal. Thank you for your patience.

7. postmortem Jun 10, 2026, 06:27 PM UTC

   Issue: Authentication tokens not received via email for users accessing Exclaimer Portal Incident Length: 7 hour\(s\) and 17 minutes Incident Date: 25/05/2026, UTC 03:12– 10:29 UTC Incident Status: Resolved **Summary** Customers logging into the Exclaimer Portal using the Username and Password option were unable to receive authentication tokens for a period of time, preventing them from being able to access the portal. The exception did not trigger alerting that engaged our key engineering team, resulting in an extended impact time. **Root Cause** A process-level exception had occurred and not been successfully restarted. This resulted in token codes being generated but not emailed to users when required. **Mitigation** A rollback of the key service that included this process resolved the issue and allowed for a backlog of token code messages that had been generated to be cleared and distributed, which then restored standard service. Further improvements to internal escalation and alerting processes have been put into place to reduce the delay in acknowledging the issue and beginning resolution steps over public holidays. **Incident Timeline** 03:12 - Exclaimer Engineers identify a possible issue with customers being unable to log in to the portal when using a Username and Password. 03:36 – Further testing confirms the issue is impacting the authentication code stage, where the email is never received. Other forms of authentication are working as expected. 03:18 – Status page is updated to ensure customers are aware of the issue and to advise alternative login methods. 07:37 – Exclaimer Engineering is alerted and begins to investigate the scope of the issue. Additional engineering resources are called in to investigate the cause. 08:51 – A rollback of the last set of changes made to the service is performed. Testing begins to see if the issue continues 09:04 – Exclaimer Engineers identify the issue is still ongoing despite the rollback work 09:26 - Engineers confirm that the token codes are being generated as expected, indicating the service runs as anticipated to ensure accounts are secure. 09:40 – Consistent replication of the issue is confirmed, expediting testing and remediation processes. 09:59 – Exclaimer Engineers complete further system rollbacks to address the issue. 10:19 – Engineering note that a group of token code messages are confirmed to have been sent as expected and are also received within the mailboxes of accounts. 10:29 – Log review indicates that all submitted codes are processed as expected and new requests for token codes are received by users as expected.

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Started May 19, 2026, 04:23 PM UTC· resolved May 19, 2026, 04:23 PM UTC

1. resolved May 19, 2026, 04:23 PM UTC

   Exclaimer Customers using Exclaimer Cloud for Microsoft 365 would have encountered an error when attempting to run the connector setup wizard from the 'Manage Mail Flow' page, causing the wizard to fail to run. This issue would have no impact on customers who have not previously run the Connector Setup wizard for Microsoft 365

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Started May 11, 2026, 05:33 PM UTC· resolved May 12, 2026, 08:43 AM UTC

1. investigating May 11, 2026, 05:33 PM UTC

   Exclaimer Engineers are looking into an issue that will result in customers seeing signatures are applied after a short delay at this time. More information will be provided when possible.

2. monitoring May 11, 2026, 05:45 PM UTC

   Engineers have confirmed that the issue has been addressed with additional capacity being utilized within the UK. They are now monitoring for any further issues.

3. resolved May 12, 2026, 08:43 AM UTC

   This incident has been resolved.

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Started Apr 24, 2026, 04:03 PM UTC· resolved Apr 25, 2026, 08:41 AM UTC

1. investigating Apr 24, 2026, 04:03 PM UTC

   We are currently investigating issue with Portal access and signature imprinting issue. This is related to the Azure outage - https://azure.status.microsoft/en-us/status

2. identified Apr 24, 2026, 06:44 PM UTC

   We are observing improvements in signature imprints and portal access. However, intermittent failures may still occur as the underlying Azure issue is not yet fully resolved. We continue to actively monitor progress from Microsoft and will provide updates here as more information becomes available.

3. identified Apr 24, 2026, 10:07 PM UTC

   We are continuing to see improvements, with no further reports at this time. Microsoft is still in the process of rolling out changes across the region, and we are closely monitoring progress. We will provide further updates as they become available.

4. resolved Apr 25, 2026, 08:41 AM UTC

   The azure incident has been resolved and our Exclaimer engineers we have been able to restore full functionality for our customers. Extended monitoring has not indicated any other outstanding issues at this time. If you are continuing to have issues with Exclaimer signature imprinting or the portal, please reach out to our support team, who will be happy to help.

5. postmortem May 22, 2026, 04:16 PM UTC

   Issue: Signature tester errors when testing Client-side Signatures Incident Length: 8 hour\(s\) and 2 minutes Incident Date: 21/04/2026, UTC 10:06– 18:08UTC 21/04/2026 Incident Status: Resolved **Summary** Attempting to run a Client-side signature test within the Exclaimer Portal resulted in an error message being provided within the Portal. Signatures continued to be applied to messages as expected for both Server-Side and Client-Side offerings. **Root Cause** An update to the Signature Tester introduced a new element that was not currently required, but was being expected, causing the tester results window to fail to load and preventing the results window from being generated within the portal only. **Mitigation** Once the issue had been identified by our Engineering team, the change was reverted, restoring full service to the signature tester within the Web Portal. **Incident Timeline** 21/04, 10:06 – A new deployment to the signature tester was released from testing environments to live servers. 17:30 – Customer reports are confirmed by the support team when speaking with a customer who reports that the tester is failing to display a result. 17:32 - Support confirms that the issue is present in multiple regions. 17:40 – Engineering teams are notified of the issue. 17:52 – Engineering teams are able to roll back the deployment to the UK region. 17:54 – Support team confirms the issue is no longer occurring within the UK region. 18:08 – Rollback completed across all regions. 18:16 – Exclaimer Support confirms that the issue has not reoccurred since the rollback was completed.

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