[thelist] Mails bouncing - security issue?

[Mark Howells]

Hi all

We're getting an odd problem at work, where we'll get an email bounced
back to us occasionally with the following message.

> The following message could not be delivered because the address
> [RECIPIENT EMAIL ADDRESS] was rejected by host [RECIPIENT EMAIL HOST]
> ([RECIPIENT HOST I.P.]).
> 550 This entry was last confirmed open on 3/25/2002
> Reporting-MTA: dns; mountain.ch
> Arrival-Date: Thu, 26 Sep 2002 16:12:31 +0200
>
> Final-Recipient: rfc822; [RECIPIENT EMAIL ADDRESS]
> Action: failed
> Status: 5.0.0
> Diagnostic-Code: smtp; 550 This entry was last confirmed open on
> 3/25/2002

Anyone know what may be causing this? It doesn't just happen with one
recipient, but apparently at random.

Thanks & regards
Mark Howells
<http://www.mark.ac/>
AIM: mhoaim