Postfix as the default MTA?

[Matt Zimmerman]

On Fri, Sep 14, 2007 at 07:02:10PM +0200, Soren Hansen wrote:
> Many (all?) of them state a preferred mta by putting "postfix |
> mail-transport-agent" or "exim4 | mail-transport-agent" in their
> "Depends:".  This preferred MTA reflects the preference of the
> respective Debian maintainers of the dependent packages. We, however,
> have a tradition for preferring postfix. On the server team, we've
> discussed this and would like to suggest that all packages that state a
> dependency on mail-transport-agent always must prefer postfix.

Thanks for raising this; it's been a bit of a wart for some time now.

> [...]
> So, the question here is: Does anyone have any objections to
> 
> a) our preferring postfix over exim4?
> or
> b) carrying a diff against Debian for this purpose alone? 

The dependency only commonly comes into play in (I think) the following
cases:

- A task is selected during installation which requires an MTA

- The admin installs a package which requires an MTA, but doesn't have one
  installed yet

In the former case, the postfix dependency means that they get Postfix in
favour of the other choices available, without an opportunity to make a
selection.  If they want a different one, they install it manually (and the
default one is removed).  If they don't want a different one, they at least
get a consistent result.  So I think it's important to have a standard MTA
dependency for packages used in installation tasks.

In the latter case, the tools explain what they're going to do before they
do it, and again, the admin can select a different one without too much
trouble.  I think it's less important in this case that the default always
be consistent, but it would still be nice.

I rather like Stefan's suggestion, which gives us the best of both worlds (a
consistent default MTA and no unnecessary deltas from Debian).  However, it
requires that Debian adopt the change, so this would need to be discussed on
Debian lists.

-- 
 - mdz