One of our customers sent in a ticket complaining about not receiving email:
I sent myself an email to [customer's email address at their ISP] and it came back in less than 5 secs.
I sent myself an email to [customer's email address on our server] and it NEVER came back.
What is happening?
I checked the mail logs and they didn't show anything. I then sent email to the customer's address on our server, and got the following back:
From: Mail Delivery Subsystem <MAILER-DAEMON@XXXXXXXXXXXXXXX>
Subject: Returned mail: see transcript for details
Date: Wed, 7 Dec 2005 12:52:12 -0500
The original message was received at Wed, 7 Dec 2005 12:52:11 -0500 from root@localhost----- The following addresses had permanent fatal errors ----- [address to customer's ISP]
(reason: 550-[our server IP address] blocked by ldap:ou=rblmx,dc=XXXXXXX,dc=XXX) (expanded from: <XXXXXXXXXXXXXXXXXXXXXXXXX>) ----- Transcript of session follows ----- ... while talking to XXXXXXXXXXXXXXXXXXXXX.: >>> MAIL From:<support@XXXXXXXXXXX> SIZE=1311 <<< 550-[our server IP address] blocked by ldap:ou=rblmx,dc=XXXXXXX,dc=XXX <<< 550 Blocked for abuse. Please send blacklist removal requests to XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX - Be sure to include your mail server IP ADDRESS. 554 5.0.0 Service unavailable
This is a major problem.
Basically, our customer's ISP is blocking our server because it sent too much spam to towards our customer's ISP. Well, yes, because it's forwarding email, including all the spam. So of course it's going to look like our server is spamming.
I could write to XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX and say that this is a shared webhosting server and that we'll filter for spam and sorry about that, but we're already filtering spam for this client (although apparently not filtering enough). And even if they remove our server, there's no guarentee that sometime in the future they won't block our server due to excessive levels of spam coming from our server (because spam never stops).
Well, I'll write to the address anyway and profusely apologize and all that, and hope they'll remove the block.