[Mister_Magotchi]

I know this isn't the right forum for this, but there isn't a forum with a closer match for this kind of topic that I know of. I also don't know if anyone cares about this issue.

Anyway, here goes:

Email from the forums here fails the Postfix "reject_unknown_client_hostname" restriction and probably other similar restrictions in other MTAs.

Mail comes from "*************.89", the PTR record of which is "forums.alliedmods.net", but the A record of "forums.alliedmods.net" is "141.101.125.151" (presumably a CloudFlare IP).

To fix this, "*************.89" would need to have a PTR record pointing to some hostname (maybe "web01.alliedmods.net" as the server uses for its current HELO name), and that hostname would need to to have an A recording pointing back to "*************.89". It's a bonus if the HELO name matches that same reverse hostname, but that rule is rarely enforced.

[h3bus]

Yes I confirm this, the DNS is misconfigured. I've already sent that info through the contact form but nothing has changed since.

I had to lower my postfix rules strength only for alliedmods.

[h3bus]

I'm bumping this because I had to revert back the original reject_unknown_client_hostname configuration to avoid receiving to many junk mails. Thus I reject alliedmods mail agin.

Seriously, if you don't know how to properly setup a mail server, learn how to do it or leave this task to a company that knows what to do.

Setting up a valid IP->RPTR->DNS->IP is not THAT complicated!

[asherkin]

Unfortunately, what you perceive is the issue (which is indeed trivial to rectify), is completely unrelated to the actual underlying problem.

[h3bus]

Well what is the undelying problem?

What I see from my postfix server:
- Your smtp server HELO indentification is web01.alliedmods.net
- Your smtp server IP is *************.89 which reverse resolves to forums.alliedmods.net
- forums.alliedmods.net resolves to 141.101.125.151
- web01.alliedmods.net does not resolve to any IP

Their are multiple way to fix this, the proper one would be to setup the reverse DNS of *************.89 to web01.alliedmods.net and add a DNS entry for web01.alliedmods.net to *************.89
Additionaly setting up an SPF record allowing web01.alliedmods.net as a sender for alliedmods.net would be great.

I really don't understand what kind of setup/ISP you might have that won't allow such setup.

[h3bus]

Also I would add that correcting these settings may significantly lower your MX load as:
- The default answer is 450 (temporary failure), thus your smtp will keep outgoing mail in queue until it successfully deliver it (never), or the delivery timeout is reached (might be 4 days, depending on your configuration)
- A lot of MX server share the same configuration and outgoing queue might grow big!

[Mister_Magotchi]

asherkin: Could you please at least give a quick note on what "the actual underlying problem" is?

I'm also just generally bumping this, since I still feel it to be an important problem to be solved, and based on my outside-looking-in knowledge, I believe it should require only a minimal amount of work.

[asherkin]

Originally Posted by Mister_Magotchi asherkin: Could you please at least give a quick note on what "the actual underlying problem" is?

The forum is using the "wrong" SMTP server.