[Info-vax] Decuserve.org - Anyone know why it's down?

[JF Mezei]

On 15-01-06 08:16, Bill Gunshannon wrote:

> But people should realize, places that accept email from sites who's
> A Record and PTR Record do not match are mis-configured. 

Nop.

Consider one of the large ISPs in Canada (Rogers). They have outsourced
email to Yahoo.  So a may from name at rogers.com is actually processed and
then sent by a server whose reverse translation points to a Yahoo.com host.

Bell Canada, not to be outdone, outsoruced its mail to microsost/hotmail
(or whatever it is called this week)

On a more concrete example:

from jdoe at ibm.com   will likely be processed by a server whose IP
address is reversed translated to mta3872.ibm.com but whose helo may be
mta.ibm.com

This is why SPF records exist, to list the hosts authorized to send mail
on behalf of a domain.