5 Nov
1997
5 Nov
'97
1:34 a.m.
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@get-more-hits.com>) rejection: 451 <tcsender@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