After a recent upgrade of our system from ZCP to Kopano (which included upgrading the Gateway server) we noticed that our IMAP Clients will auto-save multiple copies of the same message to the Drafts folder. And even after the message is sent, multiple copies remain in the Drafts folder…
The client we are using is Thunderbird (not all are the most recent but many are version 52). There are a number of Knowledgebase articles on the Internet about Thunderbird and GMail with this exact same problem, but none of the workarounds seem to fix the problem.
Is anyone else having this problem? Is there a way to fix it?