When syncing your email account using IMAP and Apple Mail and your folders do not display properly, you may have problems saving emails to your drafts, deleted items and sent folders.
Apple Mail has an incorrect IMAP Path Prefix
Configure Apple Mail to use the correct IMAP Path Prefix for your IMAP server.
How to set IMAP Path Prefix in Apple Mail
- Open Apple Mail
- Click Mail, Preferences.
- Select your email account and click Advanced
- Set the IMAP Path Prefix to INBOX (all uppercase). Close the window and if prompted, Save changes.