[Pkg-exim4-users] Catch all mailbox

[Marc Haber]

Hi Martin,

can you please subscribe to the list with the address you are posting
from, so that I do not have to manually approve your messages? The
alioth moderation process is currently broken so that I do not get any
reminders that there are mesages in the moderator queue.

On Mon, Apr 11, 2005 at 09:06:54PM +0100, Martin Fraser wrote:
> The problem was the fact that it was matching my random address to the 
> catchall *: postmaster, then checking that and finding an alias for 
> root, then checking that and finding a real user name, then checking 
> that against the aliases file again and finding the postmaster catchall 
> and realising it had been checked already, it failed.

Can you document this in exim -bt output? I do not quite understand
what you mean.

There is a pitfall with catchall accounts: The catchall target will
re-trigger the catchall. This can be remedied by aliasing the target
to itself, like in:

catchall_target: catchall_target
*: catchall_target

This will prevent the catchall to trigger again on the second round.

btw, I consider having catchalls as a very bad idea in this time.

> So, I dug further and found that the real_user router appears to match 
> real user names prepended with the word real-,

Yes. This avoids forward and alias processing for real-user, which can
be used to reach users who have broken their forwarding process by
using an illegal .forward file. See th userforward router for
examples. I have also put some documentation in the real_local router
file.

> which obviously matches 
> none of my user accounts. The router that actually finds user accounts, 
> local_user, was almost the last router and as such the wildcard in the 
> aliases files matched before I could check for real user names.

This can be remedied by aliasing your catchall target to itself.

> Firstly, what does the real_user router do.

Explained above. Or should I elaborate more?

> Secondly, what was the reason for putting the local_user router after 
> the system_alises router.

To allow local user names to be overriden by aliasing. For example, I
do not want my local daemon user to receive mail. So, I alias it to
root in /etc/aliases, which prevents the local_user router from being
accessed for the local user daemon at all.

> It seems to me that this may be a mistake 

No, it's a feature.

> since my problem must happen to anyone with a wildcard in the aliases 
> file.

Wildcards are a bad idea anyway.

> I understand that I added the lsearch* to the router and therefore 
> caused the loop myself, but why in the world would it be set to check 
> the system_aliases before checking against the list of actual user accounts.

That is a good idea. Or do you want to receive mail for "bin"?

Greetings
Marc

-- 
-----------------------------------------------------------------------------
Marc Haber         | "I don't trust Computers. They | Mailadresse im Header
Mannheim, Germany  |  lose things."    Winona Ryder | Fon: *49 621 72739834
Nordisch by Nature |  How to make an American Quilt | Fax: *49 621 72739835