Hi, All of our Thunderbird installations on three computers (Win10, Win11 + iOS) are constantly updating the Sent folder. The folder is deleting and re-downloading 16 messages in a loop. This started after we migrated our website to a different host, but it is only visible in one email address's Sent folder. Other mail addresses and folders are just fine. I have no idea what the 16 messages that cause this problem are. On our server we can see that there let's say 3016 messages, and the clients keep deleting 16 (to 3000) and then re-downloading them. We have so far tried: * Repairing the Sent folder through the Thunderbird interface * Running Compact folders * Deleting the corresponding .msf files * The server's smtp + imap cache files have been purged * Uninstalling Thunderbird, deleting all Thunderbird related files and reinstalling We are running the newest version now 102.2.2 (but earlier versions have displayed the same) and IMAP.