[drwu]

Yes! I use mutt for searching, tagging, thread operations (splitting,appending etc.), bouncing, attaching other mails, deleting attachments, openpgp (personal), smime (at work), and it works with IMAP out of the box.

I am also able to integrate (a locally hosted) LanguageTool to check the grammar in the editor.

The only issue is to write emails with embedded images. But personally I don't like such emails for occupying the space of the mailbox.