Email rejected from one account on server, but not another


Well-Known Member
Sep 26, 2006
cPanel Access Level
Root Administrator
I'm having a rather confusing problem. I have several hosting accounts on my server, but I'm specifically going to refer to,, and

Let me apologize in advance if this post is confusing. I felt like I needed to give a lot of detail, though, because it's a confusing problem to have!

The problem is that when or emails people on certain ISPs, they get a notice that the email was rejected, but when I email them through, it goes through just fine. and are owned by the same client, and are used on the same computers. has about 75 POP accounts created, and is on the same IP as only has 4 or 5 POP accounts, and is on the same server, but with a different IP. The client has an internal network that I was sure was causing the problem, but I tried logging in to their Webmail and sending a test email, and it still bounced! Now I'm completely at a loss.

I asked another client on the same IP to send a test email to one of the addresses that had bounced, and they had no errors reported, either.

All 3 accounts have the same SPF record: 14400 IN TXT "v=spf1 a mx ~all" 14400 IN TXT "v=spf1 a mx ~all" 14400 IN TXT "v=spf1 a mx ~all"

The problem is currently occurring with and; both owned by AT&T. I suspect that it will occur with all AT&T owned addresses, if not others. The error message from Bellsouth stated:

host [XXX.XXX.11.16]: 550-XX.XX.XX.XXX blocked
by ldap:eek:u=rblmx,dc=bellsouth,dc=net
550 Error - Blocked for abuse.

And the error message from stated:

host [XXX.XXX.36.20]: 553 5.3.0 nlpi076,DNSBL:521< XX.XX.XX.XXX_is_blocked.__For_information_see_

Note that I typed the XX.XX.XX.XXX in place of the actual IP. In the recipients IP, the XXX.XXX is the same for both headers, but the last 2 sectors are different.

I've checked all of the blacklists, and this IP isn't listed. And as I said before, I could email the same recipients with with no problems.

I'm kind of at a loss on where to go from here! Any suggestions?



PS, I did submit an unblock request yesterday, but since it doesn't appear to be the entire IP that's blocked, I don't think it will help.


Well-Known Member
Oct 27, 2005
Actually, I'm having the same exact problem. I'm trying to resolve it, but there doesn't seem to be anything wrong with my setup.


Well-Known Member
Sep 26, 2006
cPanel Access Level
Root Administrator
Well, Serra, if no one else is reporting the problem, then somehow it's just me and you!

Are you only having problems with AT&T subsidiaries, like me, or with a different ISP?
Mar 27, 2007
cPanel Access Level
DataCenter Provider
i have the same issues

Asunto: Mail delivery failed: returning message to sender

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:

[email protected]
SMTP error from remote mail server after MAIL FROM:<[email protected]>:
host []: 553 5.3.0 flpi191 -
mBFEoRrc013851, DNSBL:521<
> >_is_blocked.__For_information_see_

------ This is a copy of the message, including all the headers. ------