So I see the following error Helo command rejected: Host not found;
in /var/log/syslog
, but when I do forward and reverse lookups on the host in question, the DNS records appear reasonable. The mail server in question, endor
, seems to otherwise be receiving mail just fine.
Why is Postfix saying this (and bonus second question, is there a setting I should change to fix it?
Email addresses changed for privacy:
Jul 20 23:35:20 endor postfix/smtpd[1503]: NOQUEUE: reject: RCPT from
bdmrob01-2.metavante.com[206.71.18.21]: 450 4.7.1
<bdmrob02.metavante.com>: Helo command rejected: Host not found;
from=<[email protected]>
to=<[email protected]> proto=ESMTP
helo=<bdmrob02.metavante.com>
But DNS looks ok:
endor% dig bdmrob01-2.metavante.com
; <<>> DiG 9.11.3-1ubuntu1.1-Ubuntu <<>> bdmrob01-2.metavante.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 32487
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;bdmrob01-2.metavante.com. IN A
;; ANSWER SECTION:
bdmrob01-2.metavante.com. 600 IN A 206.71.18.21
endor% dig -x 206.71.18.21
; <<>> DiG 9.11.3-1ubuntu1.1-Ubuntu <<>> -x 206.71.18.21
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 40586
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;21.18.71.206.in-addr.arpa. IN PTR
;; ANSWER SECTION:
21.18.71.206.in-addr.arpa. 600 IN PTR bdmrob01-2.metavante.com.
I should mention, main.cf says:
smtpd_helo_restrictions =
reject_non_fqdn_helo_hostname,reject_invalid_helo_hostname,reject_unknown_helo_hostname
grep -iE "dns|include" main.cf
please.postconf | grep lookup