[RFCI-Discuss] is a reversename a must ?

[csmailreport]

On Jan 23, 2008 3:11 PM, Jeff Pang <pangj at earthlink.net> wrote:
> So many email servers have no rDNS.So we now don't and won't in future reject those messages who are coming from the servers without rDNS names.


Well, given than in my experience, a lot of the badly configured mail servers
(= lacking a PTR record, in violation of RFC 1033)
are located in China (maybe Korea/Taiwan too...) or Russia / former
USSR countries,
I can certainly understand why you'd rather not refuse email from such hosts.

However, the reason why you don't want to block these might be exactly the same
why I refuse emails from such badly configured mail servers, actually,
so in fact our respective choices might not be that different :-P

More seriously, one important thing to consider when deciding to refuse email
based on a specific criteria is "how difficult would it be for the
remote mail system
administrator to resolve the issue and unblock itself ?"

Getting a reverse DNS setup on one's IP address doesn't sound that difficult
(just contact your business-class ISP customer service...
if they don't provide this service, they're probably a low-cost residential ISP
instead, and you shouldn't be trying to email directly anyway
but instead route your emails through one of your upstream ISP's
official mail servers)

That's one more reason why blocking based on SORBS blacklisting is totally
unreasonable (given that it's virtually impossible to get unlisted
from SORBS :-)

PS: Comcast pretends to be refusing emails from hosts lacking a PTR RR too,
according to their FAQ:
http://www.comcast.net/help/faq/index.jsp?faq=SecurityMail_Policy18784

Hope this helps,
-- Nicolas