Unix systems often needs a local mailer, but configuring and maintaining a mailer on each system is a timeloss.
You might have a gmail or google apps account. If it’s the case, you can easily configure a mailer on your systems which uses your gmail or google apps. To do so, I’ve used ssmtp and put this in /etc/ssmtp/ssmtp.conf:
That’s it, simple, effective, working …
To improve the things, maybe, we can use an IP address of the smtp server, so that if our DNS server doesn’t work, we still have mail on the system, but this has a drawback, if the server for which you gave an ip address changes or temporarly doesn’t work, you don’t have mail anymore.
ssmtp doesn’t seem to be able to have several mailhubs !