Being on helpdesk, I have noticed this quite a bit lately, a number of ISP's reject mail if you have multiple PTR records for your IP and they resolve incorrectly. Barry -----Original Message----- From: Craig Whitmore [mailto:lennon(a)orcon.net.nz] Sent: Tuesday, 15 June 2004 2:04 p.m. To: 'Regan Murphy'; 'nznog' Subject: RE: [nznog] SMTP Servers and Reverse DNS Lookup The RFC's say you cannot reject on the HELO/EHLO so their mail server is Quite Broken. Thanks Craig
-----Original Message----- From: Regan Murphy [mailto:regan.murphy(a)oasystems.co.nz] Sent: Tuesday, June 15, 2004 2:02 PM To: nznog Subject: [nznog] SMTP Servers and Reverse DNS Lookup
I was having problems sending mail to an organisation and eventually worked out that the host name and reverse dns entry did not match and therefore mail transfer was refused:
------- 220 mail.xxxbar.co.nz ESMTP NetIQ MailMarshal (v5.5.5.8) Ready ehlo hellmouth.oaxxxsystems.co.nz 554 No SMTP service here -------
As soon as I corrected my server to use the correct host name to match
the reverse (vampire.oaxxxsystems.co.nz) then mail was allowed to go through. I would assume this was a recent change by the receiving organisation as I have not had problems sending them emails before. Is this sort of configuration becoming standard for organistions? I would expect that may create problems for smaller organisations sending email directly from their in-house hosted mail server for which they have no control over reverse-dns entries.
-- Regards, Regan
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