There are a few choices to be made when selecting an MTA to install;
the first one is whether you want a send-only MTA or you need a
fully-fledged mail server.
This Unix.SE post
provides a comprehensive list of send-only MTAs available; all of them
are already packaged for Ubuntu 10.10. There are a few things you
might want to consider when choosing a send-only MTA:
whether it can queue e-mails for later delivery in case of a
failure: IIRC, only nullmailer
can do this.
whether it will replace the system mail delivery agent (look for a
line Provides: mail-transport-agent
in the output of apt-cache
show package
). If it does, then all mail originating from the
system (including reports from cron jobs, popularity statistics,
etc.) will be handled by the MTA you install: if you do not set up
correct mail aliases for root and other users, the email might
end up delivered at the wrong address (typically, some sysadmin at
your ISP). Currently, packages nullmailer
, esmtp-run
(but not
esmtp
) and ssmtp
fall into this category.
All send-only MTAs will just forward your email to another server
(called "relay host" or "smarthost"; typically it's your ISP's SMTP
server) and then let it handle all the details of real Internet
mail delivery. You need to figure out whether there are any
special requirements for connecting to the ISP server (e.g., some
kind of authentication or TLS) and choose an MTA that supports the
required features (for instance, ssmtp
does not support any kind
of authentication or SSL/TLS).
Fully-fledged mail servers include exim,
postfix, and
sendmail. The
post-installation installation script for Debian/Ubuntu will do a
great job of producing a working configuration for some common setup
(delivery of mail to the local system only; sending email through a
"smarthost" -- i.e., a mail server you funnel all your emails
through, typically your ISP's SMTP host; internet site with full
inbound and outbound connectivity). IMHO, postfix is the easiest to
run and configure, but since it's so capable, its configuration manual
is way longer than any of the send-only MTAs.
In addition, the real risk with setting up a mail server is that, if
you make a mistake in the local configuration, you end up with mail
delivered to the wrong place (read: lost) or -worse- with an
open-relay system that can be used by spammers (and, trust me, they
can find an open relay before you realize your server is one).
My advice would be then to start with a send-only MTA and then
upgrade to a full mail server only if you see the need for it (which
is not the case if you just want to send emails to your GMail
address).
Postfix is started in init.d
, so you can use update-rc.d
to disable it on startup:
sudo update-rc.d postfix disable
When you want to enable it again:
sudo update-rc.d postfix enable
Even if it's disabled you can still start it manually with sudo service postfix start
.
If update-rc.d
is not in your system, you'll have to install the package sysvinit-utils
or sysv-rc
, or similar (those are for 12.04, I don't remember if 10.04 use the same names).
As for the notifications, usually the email will give you a clue on which job sent it, but if you want to track all jobs run by cron, you can take a look at the crontab and /etc/cron.*
. See the section NOTES in man cron
for details.
crontab -l
sudo crontab -l
ls -lr /etc/cron.*
You could also check the syslog:
sudo grep -i cron /var/log/syslog
Best Answer
Ubuntu 12.04 Desktop does not include any "email program" (client or server). Still, if you wish to save about 40-45 megabytes of space, you can remove it's default email client, Thunderbird, with:
Ctrl+Alt+T
sudo apt-get remove --purge thunderbird -y
exit
.