I am running on a ubuntu 14.04 VPS and am having trouble getting opendkim to sign outgoing emails.
Also, I do not understand the results from dig -x, and I'm not sure my VPS provider entered the rDNS PTR record correctly. Here are the results returned:
$ dig -x 18.104.22.168 ; <<>> DiG 9.9.5-9+deb8u5-Debian <<>> -x 22.214.171.124 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 38970 ;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1 ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 512 ;; QUESTION SECTION: ;126.96.36.199.in-addr.arpa. IN PTR ;; ANSWER SECTION: 188.8.131.52.in-addr.arpa. 10799 IN CNAME 129.0-255.17.200.84.in-addr.arpa. 129.0-255.17.200.84.in-addr.arpa. 10799 IN PTR ozarksneighborlyexchange.com. ;; Query time: 273 msec ;; SERVER: 184.108.40.206#53(220.127.116.11) ;; WHEN: Fri Mar 25 07:13:48 CDT 2016 ;; MSG SIZE rcvd: 121
I know for example that CNAME is an alias. I expected a PTR for my domain and IP, but they seem to have only added a CNAME record. The PTR record pertains to the providers entire IP range. From what I've read CNAME records don't hold much weight for verification purposes. The score on mail-tester.com did improve from 3/10 to 4.5/10 after the CNAME was added tho.
As for the opendkim signing problem, I followed this guide: https://easyengine.io/tutorials/mail/dkim-postfix-ubuntu/ and enabled extended logging with:
# Log to syslog Syslog yes LogWhy yes SyslogSuccess yes MilterDebug 3
I see the following in the logs for a simple email to mail-tester.com:
Mar 25 11:49:35 seed05 opendkim: D05F140793: no signing domain match for 'seed05.ozarksneighborlyexchange.com' Mar 25 11:49:35 seed05 opendkim: D05F140793: no signing subdomain match for 'seed05.ozarksneighborlyexchange.com' Mar 25 11:49:35 seed05 opendkim: D05F140793: no signature data
I am also a bit confused about the role subdomains play in this. I set my VPS hostname to seed05, and added this line to my /etc/hosts file: 18.104.22.168 seed05.ozarksneighborlyexchange.com seed05
I am not sure what if anything needs to be added to my DNS that relates to a subdomain. I currently have 2 "A" records and 2 "TXT" records defined: A @ A www TXT @ v=spf1 a include:_spf.ozarksneig..... (for SPF, which seems OK) TXT mail._domainkey v=DKIM1; p=MIGfMA0GCS...... (tools seem to say this OK)
I have added postfix to the opendkim group. I see lots of references to inet but inetd is deprecated and I can't find info on how the replacement for it is configured (for example where port 8891 is defined for smtp / postfix).
So as you can see I have several points of confusion despite spending all day trying to get email to be sent more reliably. Would greatly appreciate any input / answers to this. Thx!