I use ssmtp for my MTA (mail transfer agent) under fedora. Up till now I've always just moved /usr/sbin/sendmail out of the way and symlinked it to where I have ssmtp installed. Today, after upgrading a work machine to f14, I finally bit the bullet and figured out how to set ssmtp as my MTA the proper way – through the alternatives command.
Sendmail is configured as the mta under alternatives. You can see which mta's are available by doing this:
alternatives --config mta
which shows something like this:
There is 1 program that provides 'mta'. Selection Command ----------------------------------------------- *+ 1 /usr/sbin/sendmail.sendmail
To add ssmtp, I must first install it as an alternative mta:
sudo alternatives --install /usr/sbin/sendmail mta /usr/local/ssmtp/sbin/ssmtp 20000
This says that /usr/local/ssmtp/bin/ssmtp is an alternative option for /usr/sbin/sendmail under the alternatives label of mta. The 20000 is large enough to make this particular alternative the default, though it can be changed later.
Now we can see the new configuration:
There are 2 programs which provide 'mta'.
Selection Command
-----------------------------------------------
1 /usr/sbin/sendmail.sendmail
*+ 2 /usr/local/ssmtp/sbin/ssmtp
The new entry is now the default. You can use the alternatives command to change it back later if you need to. The nice thing about using alternatives was that I didn't need to change the /usr/sbin/sendmail link at all. Alternatives takes care of that for you.
Why not just “yum install ssmtp; yum remove sendmail”? It looks like Fedora has included it since F11, and it correctly sets up the alternatives. From the spec file:
%{_sbindir}/alternatives –install %{_sbindir}/sendmail mta %{_sbindir}/sendmail.ssmtp 30 \
–slave %{_bindir}/mailq mta-mailq %{_bindir}/mailq.ssmtp \
–slave %{_bindir}/newaliases mta-newaliases %{_bindir}/newaliases.ssmtp \
–slave %{_mandir}/man1/mailq.1.gz mta-mailqman %{_mandir}/man1/mailq.ssmtp.1.gz \
–slave %{_mandir}/man1/newaliases.1.gz mta-newaliasesman %{_mandir}/man1/newaliases.ssmtp.1.gz \
–slave %{_mandir}/man8/sendmail.8.gz mta-sendmailman %{_mandir}/man8/ssmtp.8.gz
Oh sure, do it the easy way. :-)
Actually long ago when I started using ssmtp (see Linux.com article) I thought the project was basically abandoned so no one would package it. I just never checked since then. It’s nice to see it got picked up. It’s a nice replacement for sendmail.
Thanks for pointing that out.