tcsender email bombing

Wed Nov 5 06:34:24 UTC 1997

On Tue, 4 Nov 1997, John-David Childs wrote:

> You may want to change your 451 errors into 571 errors at least for this
> particular domain.  From RFC1893:

> > Nov  4 04:05:48 bconnex.net sendmail[4697]: Ruleset check_mail 
> > (<tcsender at get-more-hits.com>) rejection: 451 <tcsender at get-more-hits.com>... 
> > Domain must resolve

The usual reason cited for using 4xx errors instead of 5xx errors in this
case is that DNS failures can be transient.

Bradley