I am getting the following message when I or a client emails an aol.com address. I definitely do not have anyone sending spam on my server as there are only 10 sites, all of which are either mine or are under close supervision by me. My server is hosted by Nocster, could this be a problem across the Nocster network or could they have made a mistake about my server?

(I opened a support ticket at Nocster a few minutes ago but am wondering if you guys have any thoughts)


--------------------------
This message was created automatically by mail delivery software (Exim).

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:

rossputnam@aol.com
SMTP error from remote mailer after initial connection:
host mailin-04.mx.aol.com [205.188.156.154]: 550-The information
presently available to AOL indicates that your server
550-is being used to transmit unsolicited bulk e-mail to AOL. Based on
AOL's
550-Unsolicited Bulk E-mail policy at
http://www.aol.com/info/bulkemail.html
550-AOL cannot accept further e-mail transactions from your server or
your
550-domain. Please have your ISP/ASP contact AOL to resolve the issue
at
550 703.265.4670.

There are a couple possibilities:

1) The customer who used that IP before you may have done the spamming
2) You have open relaying, so even though you're own sites aren't sending spam, other people are using your SMTP servers to send spam.

How do I check about whether I have open relay?

Here is a start, it will run a quick test:

http://www.abuse.net/relay.html

You should also check your server for any exploited formmail scripts or anything similar. Have a look through your maillogs

If you do not have a open relay your ip could have been blacklisted, I am unsure if NOC has had trouble with this. You may try setting up a different ip for your mail servers if that is the problem (are all of your ips on the same subnet because it may not help then).

I called AOL and it turns out that when you type in my IP address to http://www.samspade.org it turns up that it has a dubious reverse DNS entry. Essentially it returns to the name of a machine that is not mine....

I wonder if this is leftover from the last user of the IP..

Anyone know how to fix this?

i think u need to have your isp change your PTR record

go to www.dnsstuff.com
and then go to Reverse DNS put your ip and look at PTR record and see if match your domain or your isp if not have your isp change it.