On Fri, January 30, 2015 11:52, Noel Jones wrote: > On 1/30/2015 10:41 AM, James B. Byrne wrote: >> I see this in our maillog: >> >> Jan 30 11:15:47 inet08 postfix-p25/smtpd[4796]: NOQUEUE: reject: >> RCPT >> from unknown[69.17.131.33]: 450 4.7.1 <mail4OA.4office.com>: Helo >> command rejected: Host not found; from=<x...@4office.com> >> to=<y...@harte-lyne.ca> proto=ESMTP helo=<mail4OA.4office.com> >> >> >> dig -x 69.17.131.33 >> >> ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.30.rc1.el6_6.1 <<>> -x >> 69.17.131.33 >> ;; global options: +cmd >> ;; Got answer: >> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28665 >> ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 >> >> ;; QUESTION SECTION: >> ;33.131.17.69.in-addr.arpa. IN PTR >> >> ;; ANSWER SECTION: >> 33.131.17.69.in-addr.arpa. 19371 IN PTR mail4oa.4office.com. >> >> The dig was run on the host rejecting the mail. Any ideas as to >> what >> is happening here? Am I missing something obvious? >> >> > > > The helo hostname, mail4OA.4office.com, does not exist. You can > tell from the "helo command rejected: host not found" in the log. > > > -- Noel Jones >
And, as one can tell from the dig, mail4oa.4office.com. does exist. Capitalisation is not significant in DNS. Host name mail4OA.4office.com is not the same as mail40A.4office.com. But, it should be considered the same as mail4oa.4office.com. -- *** E-Mail is NOT a SECURE channel *** James B. Byrne mailto:byrn...@harte-lyne.ca Harte & Lyne Limited http://www.harte-lyne.ca 9 Brockley Drive vox: +1 905 561 1241 Hamilton, Ontario fax: +1 905 561 0757 Canada L8E 3C3
