Hello all I'm getting these mail warnings in the log. Code: warning: hostname mail.gw.govt.nz does not resolve to address 192.88.190.2 nslookup produces this responce. Code: root@mx:~# nslookup 192.88.190.2 2.190.88.192.in-addr.arpa name = wrcipgw.wrc.govt.nz. 2.190.88.192.in-addr.arpa name = mail.gw.govt.nz. Authoritative answers can be found from: 190.88.192.in-addr.arpa nameserver = ns.datacom.co.nz. 190.88.192.in-addr.arpa nameserver = ns1.datacom.co.nz. ns.datacom.co.nz internet address = 202.27.76.100 ns1.datacom.co.nz internet address = 202.27.77.100 However dig produces this responce. Code: root@mx:~# dig mail.gw.govt.nz ; <<>> DiG 9.11.5-P4-5.1+deb10u2-Debian <<>> mail.gw.govt.nz ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 10156 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 3, ADDITIONAL: 5 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ; COOKIE: 7f068b2e8c0537b8dc866d2a5f5eeff78365fc72baf395e8 (good) ;; QUESTION SECTION: ;mail.gw.govt.nz. IN A ;; ANSWER SECTION: mail.gw.govt.nz. 300 IN CNAME custom.engage.ubiquity.co.nz. custom.engage.ubiquity.co.nz. 84231 IN A 103.241.84.35 ;; AUTHORITY SECTION: ubiquity.co.nz. 84231 IN NS ns2.discountdomains.co.nz. ubiquity.co.nz. 84231 IN NS ns1.discountdomains.co.nz. ubiquity.co.nz. 84231 IN NS ns3.discountdomains.co.nz. ;; ADDITIONAL SECTION: ns1.discountdomains.co.nz. 84231 IN A 202.174.116.15 ns2.discountdomains.co.nz. 84231 IN A 202.174.114.163 ns3.discountdomains.co.nz. 84231 IN A 13.75.179.10 ns3.discountdomains.co.nz. 84231 IN AAAA 2603:1010:2::14e ;; Query time: 35 msec ;; SERVER: 192.168.1.20#53(192.168.1.20) ;; WHEN: Mon Sep 14 16:22:15 NZST 2020 ;; MSG SIZE rcvd: 274 I'm not sure if this is a configuration issue at my end or at the senders end. I am expecting emails from the domain in question, so I'm not surprised to see any messages from the domain in question. But I am surprised I can't recieve those emails. Your comments would be most helpfull. Regards Fred
Code: $ host mail.gw.govt.nz mail.gw.govt.nz is an alias for custom.engage.ubiquity.co.nz. custom.engage.ubiquity.co.nz has address 103.241.84.35 custom.engage.ubiquity.co.nz mail is handled by 10 m4.ubiquity.co.nz. custom.engage.ubiquity.co.nz mail is handled by 10 m2.ubiquity.co.nz. custom.engage.ubiquity.co.nz mail is handled by 10 m3.ubiquity.co.nz. custom.engage.ubiquity.co.nz mail is handled by 10 m1.ubiquity.co.nz. So the warning is correct, mail.gw.govt.nz does not resolve to the used IP address. My interpretation is email server at IP address 192.88.190.2 tried to send to your server, and claimed it is mail.gw.govt.nz. Your e-mail server caught this and warned, maybe refused to accept the e-mail. Spammers do things like that, claiming to be someone else. Or it is a misconfigured e-mail server, but that must be corrected by admins there, you can not fix that.