Since I upgraded to 1.5.16, I'm observing some bizarre behaviour related to Reply-To. The situation is similar to the one described by Derek in #2304. Actually, I just found this in 1.5.15 as well, so who knows when the change actually occurred.
Basically, I tried to reply to a ticketing system which has the Reply-To: set accordingly, but this gets ignored completely, and the reply goes to the To:. No setting of reply_to changes anything. But: this _only_ happens when hostname is set explicitly in .muttrc! Commenting out hostname isn't really an option, as I use it to masquerade my From: address. I guess my .muttrc hasn't changed much in years.
