Balsa is a highly configurable and robust lightweight mail client. It supports both POP3 and IMAP servers as well as the mbox, maildir and mh local mailbox formats. Balsa also supports SMTP and/or the use of a local MTA such as Sendmail.

Some of Balsa's other features include:

* Allowing nested mailboxes
* Printing
* Spell Checking
* Multi-threaded mail retrieval
* MIME support (view images inline, save parts)
* GPE Palmtop, LDAP, LDIF and vCard address book support
* Multiple character sets for composing and reading messages
* File attachments on outgoing messages
* GPG/OpenPGP mail signing and encryption

Support for Kerberos and SSL are also included.

Similar applications: 
Thunderbird, Outlook Express, Windows Mail, Windows Live Mail, Mail