Mutt is a sophisticated text-based Mail User Agent. Some highlights:
* MIME support (including RFC1522 encoding/decoding of 8-bit message
headers and UTF-8 support).
* PGP/MIME support (RFC 2015).
* Advanced IMAP client supporting SSL encryption and SASL authentication.
* POP3 support.
* ESMTP support.
* Message threading (both strict and non-strict).
* Keybindings are configurable, default keybindings are much like ELM;
Mush and PINE-like ones are provided as examples.
* Handles MMDF, MH and Maildir in addition to regular mbox format.
* Messages may be (indefinitely) postponed.
* Colour support.
* Highly configurable through easy but powerful rc file.
* Support for compressed mailboxes.
* An optional Sidebar.