[BlueOnyx:10582] Re: Email for all users rejected with "User unknown"

[Michael Stauber]

Hi William,

> We have a BlueOnyx (5108R) server that is rejecting inbound mail for all
> users with "User unknown".  It also rejects outbound mail from all users. 
> Does anyone have a suggestion?
>
> SENDMAIL VERIFY USER:
> [root at taveuni init.d]# sendmail -bv william.thackrey at domainname.com
> william.thackrey at domainname.com... deliverable: mailer local, user
> localusername

Ok, that looks good.

> mail from: william.thackrey at vsitedomain.com
> 550 5.1.1 william.thackrey at vsitedomain.com... User unknown

Are you by chance using C-Name records for your DNS? If that's the case, then 
Sendmail cannot look aliases.

Most cases like this are revolve around one (or multiple) of these issues:

- Sendmail needs a restart to rehash the databases
- Usage of C-Name DNS records
- Email server alias problems
- Incorrect A-Records and/or MX-Records

Please check this guide:

http://www.solarspeed.net/otrs/public.pl?Action=PublicFAQZoom;ItemID=16

Change your DNS for one of the sites to the example listed there and see if 
that makes any difference.

-- 
With best regards

Michael Stauber