Heirloom mailx is a mail application that is based on Berkeley Mail and offers the features of both System V and POSIX mailx commands.
The tool is designed to comply with the mailx command specifications of IEEE Std 1003.2-1992 (POSIX.2) and IEEE Std 1003.1-2004 with XSI extensions (SUSv3). In addition to these specifications, Heirloom mailx supports the MIME specifications that enable it to send and receive attachments and code and decode international character strings.
Users can convert between different character encodings if their system libraries provide the appropriate support. Moreover, when combined with a UTF-8 terminal, the software application supports almost all international languages.
Another useful feature of Heirloom mailx is its support for IMAP. With OpenSSL or Mozilla NSS, users can use IMAPS to manage and store folder hierarchies on remote servers. This feature is particularly useful for people who use more than one computer to access their mail. The program also supports caching and disconnected operation of IMAP folders, which speeds up operation while in online mode.
Users can read messages on remote servers through POP3 support. This feature enables users to access their POP3 accounts almost like local mail folders. Moreover, SMTP support enables users to send messages directly to a remote server without the need for a local sendmail interface setup.
The program also features a Bayesian junk mail filter that follows Paul Graham's article "Better Bayesian Filtering." Additionally, detail improvements over previous implementations of Mail/mailx include features such as IMAP-style search methods, scoring, maildir folder support, and an option to set the From: address directly.
Heirloom mailx is extensively described in its manual page mailx(1), which provides both introductory material and comprehensive reference documentation. The most recent release includes an option to discard empty messages, support for SMTP AUTH PLAIN, and outgoing character set selection that works for each part of a multi-part message separately.
Version 12.4: N/A