msmtp is an SMTP client.
In the default mode, it transmits a mail to an SMTP server (for example at a free mail provider) which takes care of further delivery.
To use this program with your mail user agent (MUA), create a configuration file with your mail account(s) and tell your MUA to call msmtp instead of /usr/sbin/sendmail.
Features include:
- Sendmail compatible interface (command line options and exit codes).
- TLS/SSL support, including client certificates.
- Authentication methods PLAIN, LOGIN, CRAM-MD5, EXTERNAL, GSSAPI, SCRAM-SHA-1, DIGEST-MD5, and NTLM.
- PIPELINING support for increased transmission speed.
- DSN (Delivery Status Notification) support.
- RMQS (Remote Message Queue Starting) support (ETRN keyword).
- IPv6 support.
- LMTP support.
- Support for multiple accounts.