Why Can I Not Delete This Email?

Episode 1739 (2:00:44)

Greg from Cardiff By the Sea, CA
Mail

Greg has email messages that he can't throw away. When he tries to trash it, he gets an error message. He's using Apple Mail. Leo says the message is actually deleted, but the entry is persisting for some reason. Within the mail app, select the mailbox in question and rebuild it. It will rescan the database and rebuild the index. Here's how - https://support.apple.com/guide/mail/rebuild-mailboxes-mlhlp1227/mac