Multiple signatures appearing in some messages

Update timeline

1. investigating Apr 15, 2026, 11:03 AM UTC

   Exclaimer engineers are currently investigating a problem where signatures are being applied to messages even though a signature is already present on the most recent message. The issue does not appear to be impacting all mail at this time. We will provide more information as it becomes available.

2. identified Apr 16, 2026, 03:23 PM UTC

   Exclaimer Engineers have been able to identify changes being made by Outlook when the email signature is applied, and then the email is saved as a draft. Resulting in a secondary signature being applied server-side if this is also enabled. The issue is being raised with Microsoft directly to understand this behavioural change further.

3. identified Apr 17, 2026, 09:42 AM UTC

   Exclaimer Engineers have made a change to signature generation to help prevent the issue from occurring for client-side signatures. We are continuing to raise the issue with Microsoft to gain a more in-depth understanding of the problem.

4. resolved Apr 30, 2026, 11:11 AM UTC

   Exclaimer Engineers have been able to release a change to the Add-in at the start of this week, alongside a fix that was released by Microsoft, and the issue no longer looks to be occurring frequently within messages. If you are still seeing duplicate email signatures being applied. Please reach out to our support team, who will be happy to help.