Why Can’t I Delete My Email From Apple Mail in Mac OS?

Problem

When you delete an email in Apple Mail using IMAP, the following error can occur:

The IMAP command “UID COPY” (to Deleted Messages) failed for the mailbox “INBOX” with server error: Failed to save copy of message..

Symptom

1. Apple Mail will not delete an email.

Cause

Apple Mail is unable to move the message to the Trash mailbox.

This is a known bug with Apple Mail.

Resolution

Disable Move deleted messages to the Trash mailbox.

1. Open Mail.
2. Open Preferences.
3. Select Accounts.
4. Select your Account and click Mailbox Behaviors.
5. Untick Move deleted messages to the Trash mailbox.
6. Close Preferences.
7. Click Save.

Enable Move deleted messages to the Trash mailbox

1. Open Preferences.
2. Select Accounts.
3. Select your Account and click Mailbox Behaviors.
4. Tick Move deleted messages to the Trash mailbox.
5. Close Preferences.
6. Click Save.