noahboegli
commented
1 year ago Soooo, as it turns out it was my fault.
By default, Thunderbird places a copy in the "Sent" folder. This seems to be already done by davmail, and with that the Exchange server behind picks it up twice and sends it twice.
If anyone has the same issue in the future: Settings > Account Settings > Copies & Folders
I have davmail configured with EWS on two different Exchange servers (running twice with two properties files)
The e-mails are getting sent twice. The issue happens on the two servers which share nothing in common.
I don't know what I need to provide, but I'm happy to provide logs or configuration extract that may help diagnose the issue