[Web-cyradm] installing on suse 9.1

[Elvis]

OK all installed, and I can add users and log in, but not send mail. I 
have not gone for smtp auth yet (wanted to keep it simple first!). I 
think I can see what the problem is: usernames are in the format 
user.mydomain.com - they can authenticate fine against cyrus with this, 
but sending a mail does not work, I think because it is looking for just 
user not user.domain.com.

Here is my postfix log:
Nov 25 16:10:31 mail postfix/smtpd[8195]: connect from localhost[127.0.0.1]
Nov 25 16:10:31 mail postfix/smtpd[8195]: 599041A6AA: 
client=localhost[127.0.0.1]
Nov 25 16:10:31 mail postfix/cleanup[8200]: 599041A6AA: 
message-id=<200411251610.31254.elvis@<changed.mydomain.com>>
Nov 25 16:10:31 mail postfix/qmgr[8052]: 599041A6AA: 
from=<elvis@<changed.mydomain.com>>, size=528, nrcpt=1 (queue active)
Nov 25 16:10:31 mail postfix/smtpd[8195]: disconnect from 
localhost[127.0.0.1]
Nov 25 16:10:31 mail postfix/error[8202]: 599041A6AA: 
to=<elvis.<changed.mydomain.com>@<changed.mydomain.com>>, 
orig_to=<elvis@<changed.mydomain.com>>, relay=none, delay=0, 
status=bounced (User unknown in virtual alias table)
Nov 25 16:10:31 mail postfix/cleanup[8200]: 8F9841A6D0: 
message-id=<20041125161031.8F9841A6D0 at mail.microlinkhouse.microlink.net>
Nov 25 16:10:31 mail postfix/qmgr[8052]: 8F9841A6D0: from=<>, size=2478, 
nrcpt=1 (queue active)
Nov 25 16:10:31 mail postfix/qmgr[8052]: 599041A6AA: removed
Nov 25 16:10:31 mail postfix/error[8202]: 8F9841A6D0: 
to=<elvis.<changed.mydomain.com>@<changed.mydomain.com>>, 
orig_to=<elvis@<changed.mydomain.com>>, relay=none, delay=0, 
status=bounced (User unknown in virtual alias table)
Nov 25 16:10:31 mail postfix/qmgr[8052]: 8F9841A6D0: removed

As you can see, this is looking for user.domain.com at domain.com

Im sorry, I'm sure this is fairly easy to fix, but could someone please 
point me in the right direction?

Thanks,
H