Comment 29 for bug 105736

I am running Mutt 1.5.21 on Debian Wheezy and had the same issue. Unfortunately, none of the advice on this page helped (including the installation of muth-patched; I did not try recompiling mutt with openssl, however.).

What solved it for me was setting imap_keepalive to a small enough number. In my muttrc, it was set to 300. When I changed this to 10, the packet length errors stopped! i.e.,

set imap_keepalive = 10

Good luck,

RK