mail problem

Hello swim1968,

Thank you for participating in the Apple Support Communities! We understand that you're encountering an "APPEND" error with an IMAP account in Mail on your Mac.

Does this error occur after performing a specific action? If so, what action? The following resource also provides some troubleshooting suggestions that may be helpful to review:

Troubleshoot email problems in Mail on Mac - Apple Support

Let us know the answers to the questions above and we'll go from there.

Take care.

Hi swim1968,

Thanks for getting back to us. Let's try changing Mailbox Behaviors so 'All Sent' is selected under the Sent Mailbox setting:

Change Mailbox Behaviors preferences in Mail on Mac - Apple Support

Once you've changed that, let us know if you continue experiencing the error.

Cheers.

swim1968 wrote:

The IMAP command “APPEND” (to INBOX) failed with server error: APPEND Contains Deleted flag.

See if there is anything here:

https://www.reddit.com/r/mac/comments/k1c8es/solution_to_imap_command_append_to_inbox_failed/

Hi swim1968,

Thanks for getting back to us. We'd like to have you contact Apple Support for a closer look at this behavior. You can reach them using the following link:

Get Support

Take care.