When i get a new user i always set a "catch all" in the alias field.
Now i've got a user that can't receive certainnname@hisdomain.com
All the other aliasses one can think of arrive.

Certainname is NOT his user name, so it sould be redirected by the catch-all.
creating a user "certainname" fails :
invalid or conflicting email aliasses "certainname"

So i guess there is somewhere on the raq already a user "certainname", that should make no difference for the aliasses.

Any ideas ?

People have had problems with 'admin' and 'postmaster' but other than that, I don't know. Is it just a random username (alias) that fails?

The name is "pol"
That does not seem like something special to me ?

Check out /etc/mail/ and look in those alias files for a user named pol.

There are 5 files in that dir:
sendmail.hf
sendmail.cf
popip.db
access.db
access

I did a search in all 5 of them, in none of them a user "pol"is found :(

What raq are you using? On my raq4, there are a bunch of alias files in /etc/mail/ that direct mail for all my domains.

Try locate aliases and see where those files are.

ok here the results :

[root@www admin]# locate aliases
/home/sites/site11/web/cgi-bin/home/data/templates/newsite/aliases.txt
locate: decode_db() aborted. Corrupt database?
[root@www admin]#

I always get this sort of messages when doing a locate, the raq is still running fine apart from a few strange things.