Mutt crashes when sending mail in batch mode, if sendmail fails. This is because curses is automatically disabled if standard input is not a tty, but yet, mutt attempts to use the internal pager to display the sendmail output. This results in a segfault. The easiest solution is to add, at line #79 of main.c, the following two lines: if (option(OPTNOCURSES)) Pager="cat"; This tells mutt, if curses is not in use, to simply use cat to dump the output. It is an easy fix, and it works.
Sorry for being so late. Can I ask you to get this fix to upstream? I'm rather busy these days to do it myself. If you aren't going to do so, please reopen this bug. Thanks a lot. - ferdy