Is it possible to alter outgoing emails with mutt? I need it at the MIME level, just before a message is passed on to an SMTP server.
For example: My language uses diacritics, but there are still some people with old email clients that can't handle it. It would be convenient if I could add another MIME part to a message with a variant with stripped diacritic accents.
I could create some kind of SMTP filter, but then I'd lose the possibility of giving the sender some feedback and recovery in the case of an error. If for some reason the filter failed, I'd like to display a message to the user and ask how to continue.