The attached gzipped mbox appears to trip up the emacs interface. The problem seems to come from the message with id CAGNsrLCWv6=36q+q+5Hc_SzgdZ2ergeKkapT7T3xXvim=2cK+A@mail.gmail.com. If you load up the thread in emacs, you get a message: mm-extern-cache-contents: Couldn't find access type Then attempting to advance past the last display message (or pressing A, or a few other things I expect gets emacs to loop indefinitely. toggle-debug-on-quit gets me this backtrace: Debugger entered--Lisp error: (quit) notmuch-show-message-extent() notmuch-show-message-bottom() notmuch-show-move-to-message-bottom() notmuch-show-goto-message-next() notmuch-show-next-open-message(nil) call-interactively(notmuch-show-next-open-message nil nil) Looking at the suspect message one sees this: --20cf305b0f1a1caaf604b875ea95 Content-Type: message/external-body; access-type=x-mutt-deleted; expiration="Wed, 8 Feb 2012 08:45:08 -0800"; length=644023 Content-Type: text/x-log; charset=US-ASCII; name="binary.log" Content-Disposition: attachment; filename="binary.log" Content-Transfer-Encoding: base64 X-Attachment-Id: f_gyejghyz0 --20cf305b0f1a1caaf604b875ea95 Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline which looks a bit odd to me (maybe mailman stripped an attachment), but I don't know much about MIME :-) Cheers, mwh