Mail server clarifications

John Pugh john.pugh at
Sat Nov 1 22:29:24 UTC 2008

Hi Tony,

Tony Yarusso wrote:
> Hi, I've been reading various wiki pages and whatnot, but I'm still
> having a little bit of trouble wrapping my head around the differences
> between various mail server software.  I've been trying to figure out
> things like MTA, MDA, etc., and it also seems like some packages are a
> mix of both, so I'd just really appreciate it if someone could take
> the time to explain in super-simple terms how everything relates
> (either by mail or IRC - I'm in #ubuntu-server as tonyyarusso with an
> always-connected screen session).  Generals would be a good start, and
> in terms of any specifics things I'd be interested in knowing more
> about include:
> postfix
is a MTA. All it does is transfer mail where you want it to go - in,
out, to any type of filter
> exim4
similar to postfix as a MTA
> dovecot
is a superb imap/pop implementation
> courier
has several components but is usually used as a imap/pop implementation
> procmail
is a MDA which is usually called or invoked by postfix
> cyrus
is similiar to dovecot as a imap/pop implementation
> qmail
is like postfix/exim in that this is a full fledged email server with
smtp, pop, imap servers all built in - a bear to configure, but a very
thorough implementation

Search engines are your friends.

These links may help...

if you want explanations - wikipedia has great descriptions of how they
all work together.

More information about the ubuntu-server mailing list