Hi, I just watched an IP address fail to be correctly resolved back to the A record. I could resolve the IP with the the same DNS on the same server myself.
These connection from a server is recorded by postfix as unknown for 212.89.81.105, yet an nslookup on this IP resolves back to the correct address:- Non-authoritative answer: 105.81.89.212.in-addr.arpa name = smtp.academicjobseu.com. Feb 15 13:06:26 logout postfix/smtpd[111]: warning: 212.89.81.105: address not listed for hostname smtp.academicjobseu.com Feb 15 13:06:26 logout postfix/smtpd[111]: connect from unknown[212.89.81.105] Feb 15 13:06:29 logout postfix/smtpd[111]: 3E42B81E81: client=unknown[212.89.81.105] Feb 15 13:06:34 logout dkim-filter[222]: 3E42B81E81: no signature data Feb 15 13:06:34 logout postfix/qmgr[111]: 3E42B81E81: from=<ag...@smtp.academicjobseu.com>, size=nnnn, nrcpt=1 (queue active) Feb 15 13:06:34 logout postfix/smtpd[111]: disconnect from unknown[212.89.81.105] Is there something that I missed in the postfix configuration? Best wishes, S