[jlgaddis]

It's pretty easy to set up OfflineIMAP or isync or similar to sync a local copy of your mail (in fact, this is a great way to back up your IMAP mailboxes whether you use mutt or not!).

Then you just point mutt at the local copy instead of the IMAP server and it doesn't matter if you're online or offline.

[freedomben]

I don't remember if OfflineIMAP was the tool I tried or not, but at the time it was quite challenging. I always suspected that rate limiting on the mail server was blowing up the download tool, but I couldn't figure it out. This was a fair number of years ago though, so things are hopefully better now.