I still mostly use mutt for my personal mail. The times I’m not using mutt, I’m not at an ssh capable terminal and end up using SquirrelMail, but that’s only in times of emergency. Anyway, I was inspired to write these thoughts down after an IRC conversation with Ari.

However, at work I’ve switched over to using Thunderbird. I like the offline folder stuff that Thunderbird does, and I recently found a silly extension that just cracks me up: the Display Mail User Agent extension. In general, Thunderbird does what I want, but I find myself missing a few features from mutt that I really wish was there.

• The ability to arbitrarily attach other mail messages. In mutt, I can tag a bunch of messages and do a tag-forward and they are all attached to the forwarded mail. Also, from the compose menu in mutt you can do a shift-A aka attach-message navigate to a mailbox, tag messages, and quit back to the compose mail, and they are attached. For the life of me, in thunderbird, I cannot figure out how to attach a message, much less a whole thread, to an arbitrary mail. I can forward a piece of mail as an attachment, but I cannot forward n>1 messages. I often send interesting threads from mailing lists to friends and co-workers and this crimps my style.
• The ability to do a reply to multiple messages and have them all quoted. Similar to the above situation, I can tag multiple messages in mutt and do a tag-reply or tag-group-reply. This feature quotes all the tagged messages as well as add all the appropriate people to the recipient list, for tag-reply this is the senders of the original mail, for tag-group-reply this is everyone who was listed as a recipient in any of the mails as well as the senders. While I don’t often use it to hit people scatter shot, I do often tag-reply to one person, when appropriate, if they have send me multiple messages in the time its taken me to get back to them.
• Custom e-mail headers. This one is purely for amusement value and is nothing that would keep me on mutt over anything else. But it is fun, and I do have a lot defined. In any typical mail you might see something like this if you look at the headers:
  

  X-If-I-Knew-Better-I-Would-Not-Be-Running: Linux 2.6.12 i686
  X-Time-Married: 3 years, 11 months, 14 days, 4 hours, 21 minutes, 42 seconds
  X-Dinah-Lives: 1 year, 3 months, 21 hours, 38 minutes, 42 seconds
  X-Uptime: 20:48:42 up 222 days, 28 min, 5 users, load average: 0.01, 0.07, 0.07
  X-The-Amount-Of-Stuff-In-My-Inbox: 92

  They are all silly, but they keep me entertained, and no one really sees them. However, every once in a blue moon I really give someone a chuckle.

Another feature that would be nice to see in thunderbird doesn’t come from mutt but from Apple Mail in OS X. This isn’t a make or break thing since I’m not used to it, but it is a nifty feature I admire.

• The ability to multiple select mailboxes and have them mingled and threaded properly in message header/index pane. Apple Mail does this, and its very slick. Its another one of those features you don’t use all the time, but it would be often enough to make it worth while. Being able to select INBOX, Sent, and a mailing list would be nice to see the some threads properly threaded all the way through when searching for a message.

Hopefully someone has already written extensions to do this and I just need to be pointed in the right direction. If not, I’ve considered writing some of them myself, but I lack the knowledge of XUL and other technologies I would need. Anyone know any good HOWTOs to get me started? (Oh, and a device to stop time so I have time to actually work on it?)

[Update 8/16: This is a mad knowledge bomb from Mark via IRC:

15:06 <spruance> hey, keith
15:06 <spruance> thunderbird can already forward an arbitrary number of messages
15:06 <spruance> drag those messages to the “send” area of your compose window and they’ll be attached
15:06 <spruance> grab a thread handle to take the whole thread
15:07 <spruance> Similarly, you can highlight more than one message and right click and choose “foward as attachment”

Well, the arbitrary forwarding works, I just must never have multiply selected images. However, under Fedora Core 3, with Thunderbird 1.0.6-1.1.fc3 (20050720) the dragging the message into the compose/address aread doesn’t work. The attachment box opens, but no messages are attached. Mark reports this works on Mac and Windows. Damn Linux.]