ssmtp

extremely simple MTA to get mail off the system to a mail hub

A secure, effective and simple way of getting mail off a system to your mail hub. It contains no suid-binaries or other dangerous things - no mail spool to poke around in, and no daemons running in the background. Mail is simply forwarded to the configured mailhost. Extremely easy configuration. WARNING: the above is all it does; it does not receive mail, expand aliases or manage a queue. That belongs on a mail hub with a system administrator.