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Unable to pass email to a specific domain.

I have decom'd an old exchange 2000 email server.  And replaced it with a newer System running exchange 2000.  name of old email server is mail and the new email server is mx1.

After moving all jobs, mailbox's, ect over, uninstallng esm from MAIL I am having 1 problem.  It seems that I am unable to pass any email to or from AOL from my new MX1 exchange server.  I have put in spf record in my DNS, I have assured that I have mx1 in my telco provider dns. I have even requested and been accepted into AOL's whitelist.  And yet no emails are being passed sending or receiving.  I am not on anyblacklists.  I dont have open relay either.

in event viewer I have recieved.

event ID 4000  MXExchangeTrasnport
Message delivery to the remote domain 'aol.com' failed for the following reason: The connection was dropped by the remote host.

event ID 4001  MXExchangeTrasnport
The SMTP verb which caused the error is 'MAIL'.  The response from the remote server is '521-EHLO/HELO from sender x.x.x.75 does not map to mx1.x.lan in DNS
521-sending machine n'.

our outgoing email port is x.x.x.2 as well.  x.x.x.75 is the firewall.

I am totaly lost, any help is greatly appriciated.
3 Solutions
Irwin SantosComputer Integration SpecialistCommented:
you need a REVERSE DNS entry in your DNS manager.

Also, AOL is cracking down big time on SPAM.. it's shoot first and ask questions later policy.  You may in fact be on there blacklist.

Read more info on this at

Hello neonlights1111,

I agree with irwinpks.
Check out dnsreport.com. On the left side enter your domain name and click DNS Report.  Once the report generates, check the mx section for       Reverse DNS entries for MX records . If you have a big red failed next to it, its time to call your ISP. Regardless of who you registered your domain name with, or who's services you use to maintain the domain, your ISP is the only one who can add a reverse DNS entry for you. I hope for your sake that they move faster then mine. (It took mine a week to oblige)


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