postfix or exim

[Derek Broughton]

Preston Kutzner wrote:

> On May 11, 2009, at 11:19 AM, Marius Gedminas wrote:
> 
>> On Sat, May 09, 2009 at 03:05:37PM -0700, Noah wrote:
>>> I am hoping to set up an ubuntu box for handling mail.  What is the
>>> Best
>>> MTA - exim or postfix?  Is there some pages that can explain the
>>> differences?
>>
>> "The Best MTA" is a religious question.
>>
>> Postfix is the default recommended MTA on Ubuntu systems, as far as I
>> understand, from quotes like this:
>>
>>    Postfix is the default Mail Transfer Agent (MTA) in Ubuntu.
>>            -- https://help.ubuntu.com/8.04/serverguide/C/postfix.html
>>
>> I use it, I like it.
> 
> The strange thing is that exim is usually installed by default,

Not really.

> and
> usually installed as the MTA when packages are installed that require
> an MTA.  A good example of this is mailx.

Not at all, as near as I can tell.

What happens is that you install a package that has depends like "postfix    
| exim | mail-transport-agent".  If you don't have an MTA, and you don't 
ask, there, for exim, you'll get postfix.

Now, "mailutils" - which provides a version of mailx - specifies as depends 
"exim4 | mail-transport-agent", so it will automatically provide exim4 
rather than postfix, but the package "mailx", installs "bds-mailx" which 
asks for "postfix | mail-transport-agent" and will use postfix by default.

> On a fresh system, if you
> install the package mailx, it will automatically install exim for
> you. 

To be fair, I've seen that behaviour, but it isn't true in Jaunty.

> I
> still wonder why Ubuntu installs exim as the default if no other MTA
> is already installed.

_Ubuntu_ doesn't - but an individual package maintainer is free to suggest 
any particular product.  If I package up "mailfoo" and want it to depend on 
qmail, because that's what I am familiar with, I'm welcome to do that.  If I 
really want people to use it though, I need it to depend on mail-transport-
agent (and to work with any MTA) - but I might still want to recommend 
qmail, because you can guarantee that if that's my MTA I'll be better able 
to help users when they have problems interfacing with qmail, than if 
they're using postfix or exim.
> 

-- 
derek