Forum email/DNS setup needs a slight touch - Page 1
Forum section: electronics / general

author: sdancer
author_rank: Contributor
timestamp: October 14, 2015, 08:19:36 am
content: Signing up to this forum was a bit of a hassle because my mail server kept rejecting the confirmation mails due to a failing name lookup (rejecting those is a cheap way to drop over 98% of incoming mail withveryfew false positives, and such a situation can also cause issues delivering mail to services like gmail).It would help if someone added the following to the eevblog.com DNS zone:Code:eev IN A 198.1.64.143

author: EEVblog
author_rank: Unknown
timestamp: October 14, 2015, 08:54:08 am
content: Can someone else confirm this is a good/wise thing to do? (I can do it, but my knowledge is what it does is zero)Thanks.

author: Halcyon
author_rank: Unknown
timestamp: October 14, 2015, 09:47:50 am
content: Before modifying DNS records for eevblog.com I'd be asking why your mail server is failing to look up the record itself. Seems like a bit of a dodgy e-mail provider if you ask me. Here is a dump of the records for eevblog.comDave, what is the server/host eev.eevblog.com used for? Was that an old e-mail server that was changed to mail.eevblog.com later? In this case it would be OK to add the A recordeev IN A 198.1.64.143but if it's defunct maybe there needs to be a config change elsewhere from eev to mail.eevblog.comCode:eevblog.com IN MX preference: 0 exchange: mail.eevblog.com 300s (5m)eevblog.com IN TXT google-site-verification=PmgTPKVD-LSHeDPAp9iYEC2ns4zDcbLX-x0Y9pXZaIM 300s (5m)eevblog.com IN NS erin.ns.cloudflare.com 86400s (1d)eevblog.com IN NS jake.ns.cloudflare.com 86400s (1d)eevblog.com IN SOA server: erin.ns.cloudflare.com email: dns@cloudflare.com serial: 2019549702 refresh: 10000 retry: 2400 expire: 604800 minimum ttl: 3600 86400s (1d)eevblog.com IN A 104.31.74.133 300s (5m)eevblog.com IN A 104.31.75.133 300s (5m)I can see there is already an additional record for mail.eevblog.com pointing to 198.1.64.143

author: sdancer
author_rank: Contributor
timestamp: October 14, 2015, 10:00:35 am
content: Thing is, the forum mails come from a server with IP address 198.1.64.143 that identifies ("EHLO") itself as eev.eevblog.com. The standard says that the name given in the EHLOMUST resolve, which it doesn't. it can resolve to any valid address, although it is recommended that forward and backward lookup "cycle".Currently, the address reverse-resolves to eev.eevblog.com, so that's good, just the forward resolution needs to be fixed.And yes, I'm a stickler for that

author: sleemanj
author_rank: Super Contributor
timestamp: October 14, 2015, 10:34:38 am
content: Quote from: EEVblog on October 14, 2015, 08:54:08 amYes it is.Your mailserver says it is called "eev.eevblog.com"But there is no A record or CNAME for that, in other words, it doesn't exist.You should either add an A record for it, or change your mailserver's host name to mail.eevblog.com (edit: actually don't change to mail.eevblog.com, because your reverse dns also says it should be eev.eevblog.com, so just add the A record and you are golden).telnet mail.eevblog.com 25Trying 198.1.64.143...Connected to mail.eevblog.com.Escape character is '^]'.220-eev.eevblog.comESMTP Exim 4.85 #2 Wed, 14 Oct 2015 21:33:03 +1100220-We do not authorize the use of this system to transport unsolicited,220 and/or bulk e-mail.

author: madires
author_rank: Super Contributor
timestamp: October 14, 2015, 10:40:53 am
content: Quote from: EEVblog on October 14, 2015, 08:54:08 am$ host 198.1.64.143143.64.1.198.in-addr.arpa domain name pointer eev.eevblog.com.$ host eev.eevblog.comHost eev.eevblog.com not found: 3(NXDOMAIN)Yup, forward mapping for eev.eevblog.com is missing. I'd recommend to add it to make picky (meant in a positive way) MTAs happy.