Hello,
I have configured the 'helo_verify' option to perform checks on hosts
connecting to my PC. However, in the case of our mailhubs (connecting to
the PC) the email messages were rejected (I have got around this by
excluding their IP addresses). The mailhubs were rejected, as far as I can
tell, because they have 1 IP address each but 2 reverse lookup names each.
Exim seems to check the first name it receives but not the second.
E.g. (mailhub) mary.csd.plymouth.ac.uk => 141.163.66.134
141.163.66.134 => mary.csd.plymouth.ac.uk
=> mail.plymouth.ac.uk
The mailhub will issue an EHLO with the name 'mary.csd.plymouth.ac.uk', but
the DNS will return the PTR records in a random order. If the name
'mail.plymouth.ac.uk' is returned first then (it seems) the helo_verify
fails since the name is not the same as the EHLO argument.
Our second mailhub, 141.163.66.132, also has 2 PTR records.
Is there any reason why Exim shouldn't perform the reverse DNS lookup checks
against all the PTR records it receives?
Regards,
John.
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John Horne, University of Plymouth, UK Tel: +44 (0)1752 233914
E-mail: jhorne@???
PGP key available from public key servers
