Mutt is a small but very powerful text based program for reading electronic mail under unix operating systems, including support color terminals, MIME, and a threaded sorting mode.
Features
Color support
Message threading
MIME support (including RFC2047 support for encoded headers)
PGP/MIME (RFC2015)
Various features to support mailing lists, including list-reply
Active development community
POP3 support
IMAP support
Full control of message headers when composing
Support for multiple mailbox formats (mbox, MMDF, MH, maildir)
Highly customizable, including keybindings and macros
Change configuration automatically based on recipients, current folder, etc.
Searches using regular expressions, including an internal pattern matching language
Delivery Status Notification (DSN) support
Postpone message composition indefinetly for later recall
Easily include attachments when composing, even from the command line
Ability to specify alternate addresses for recognition of mail forwarded from other accounts, with ability to set the From: headers on Replies/etc. accordingly
Multiple message tagging
Reply to or forward multiple messages at once
.mailrc style configuration files
Easy to install (uses GNU autoconf)
Compiles against either curses/ncurses or S-lang
Translation into at least 20 languages
Small and efficient
It's free! (no cost and GPL'ed)
What’s new in version 1.13.3
Updated on Jan 16 2020
Version 1.13.3:
This is a bug-fix release, fixing exit screen handling and a possible segfault on imap-logout-all.
You can get and build the real latest version mutt from http://www.mutt.org. Make sure you read the INSTALL file if you need IMAP or POP support. This package really should be removed and replaced with the official link, since the one here no longer works. The ratings below are for the mutt mail client. The 'Mutt for OSX 1.2.5i' port isn't even worth rating.
This one seems to require Fink (there is a "sw" directory).
I'm still looking for a standalone GUI mutt. Something that would use the Mutt "engine" (?) if the comparison between gecko for the web and Mutt for the mail is relevant.