On Fri, 4 Apr 2003, Avleen Vig wrote:
> Well, that time in my life has finally come.
> I've grown sick of Qmail for all the usual reasons :-)
Very good :)
> I really want to move to Exim, but due to my excessive use of the
> vpopmail add-on (for managing virtual domains under a single username
> and it's own username/password db) I'm a little locked in.
No, You're not, I had started a exim-4-vpopmail config some months ago
> I have an idea of what I need to to, but would appreciate advice from
> anyone who has.. any :-)
http://mail.tmtowtdi.de/exim
> I'm thinking of using an SQL backend for authentication. This will save
> me from adding users to /etc/passwd, which I'm not too keen on doing.
> Can I add all users to a MySQL database?
Yes.
> I'm still searching documentation on exactly this works.
Search for lookup and expansions.
> I can also convert all my .qmail-* files to .forward files, so I guess
> that's OK.
The page above includes a config which can handle .qmail-* files :)
> I can also continue to use EZMLM as far as I know, so I guess that's ok.
I'm not sure on this, IIRC ezmlm depends on qmails special handling of
return-codes from pipes.
> The one thing I'm most unsure about even after reading documentation, is
> how exim handles virtual users.
In the way you want it.
> The way that seems to make sense to me, if I can use an SQB database, is
> to enter a username "foo@???", point it to a maildir and have
> all mail for it just get delivered there. Is this realistic?
Yes.
> I'm making the assumption that when it does the delivery, Exim changes
> UID to the UID of the owner of the Maildir? Otherwise how does it know
> which UID to change to?
You can tell it which user to use with the user= option in the
transport/router.
> Finally, I'm not *entirely* certain how aliasing usernames in this
> situation would work. I guess one way would be to enter then into the
> SQL database, with the same homedir as the primary account.
> A branching questioning from this would be "how would I set up a
> catch-all/wildcard account" ?
The alias would forward to the real-acount, this forwarding will be done
till a real user is reached.
> If someone could answer these for me, or point me at the right parts of
> the documentation to read, I would really appreciate it!
I think you need a bit more understanding of the general concept of exim.
Exim uses the concept of routers, they are run in the order as given in
your config-file, when the routers pre-condition are met, the router
itself starts, you can change the type of the router with the
driver-option. Depending on the driver, you have different options you can
set.
The router either changes the address(redirect router), hands it over to
a transport, defers or declines to handle the address.
The transport does the real delivery, depending on the driver and the
options you set in the transport.
In general, read the WHOLE spec.txt it will give you a very good overview
how exim works, read about the different types of routers (redirect is
VERY powerful if (ab)used correctly), read about lookups and expansions,
and you will understand ;)
Nico
