Mac Mail IMAP Error

[dgold1055]

I have a fastmail IMAP account and use Mail on the Mac. The past few days this error message keeps coming up and it is making Mail unusable for me. I have tried deleting and re-adding the account but it hasn't fix the problem. Mail on my iPad and iPhone is working find without any issues. The error message is: The IMAP command “APPEND” (to INBOX.Read Receipts) failed with server error: Too many identical emails.

Any ideas on how to fix?

 

[satcomer]

That means that you know you email server settings! Then go to Mail’s Accounts page and delete your problem connection then go to Mail’s menu selection ‘Window’ and from there click on ‘Connection Doctor’ to get all the servers in and out connections to trouble shoot your Mac Mail connections!