Mutt is a free and very powerful text-based mail client. Its very small in size. Mutt supports POP3 and IMAP protocols. Various multiple mailbox formats are like MBOX, MMDF and MH are support by mutt.
It is easy to install and using the feature of mutt, there no need of manual. The configuration automatically changes, based on recipients. An effective feature is it provides to reply or forward multiple messages at once.