Restarting sendmail sometimes will help you out.
Try this first.
Taco
----- Original Message -----
From: "D" <bqlist (at mark) distortal.com>
To: "Cobalt Mailing List" <coba-e (at mark) bluequartz.org>
Sent: Tuesday, July 03, 2007 5:26 PM
Subject: [coba-e:10301] Relaying Denied. Proper Authentication required.
> Hi all,
>
> I recently added a new domain and cannot send email to any of the users
> I have added. I get the following error:
>
> -----8<-----
>
> ----- The following addresses had permanent fatal errors -----
> <ln.admin (at mark) mydomain.co.uk>
> (reason: 550 5.7.1 <ln.admin (at mark) mydomain.co.uk>... Relaying denied.
> Proper authentication required.)
>
> ----- Transcript of session follows -----
> ... while talking to www.mydomain.co.uk.:
> >>> >>> DATA
> <<< 550 5.7.1 <ln.admin (at mark) mydomain.co.uk>... Relaying denied. Proper
> authentication required.
> 550 5.1.1 <ln.admin (at mark) mydomain.co.uk>... User unknown
> <<< 503 5.0.0 Need RCPT (recipient)
>
>
> ----- 8< -----
>
> Any ideas?
>
>
> D
>
>