Exchange 2003 SMTP communication problem

Posted on 2007-12-06
Last Modified: 2010-04-21
I have a end user that is trying to email cplazola and we get this error message: on 12/6/2007 12:36 PM
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            < #5.5.0 smtp;550-JunkMail rejected - (>

Is there a problem with my email server?  
Question by:Bulls-Eye
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Accepted Solution

notfuzzi earned 250 total points
ID: 20423451
Looks to me like it was blocked as spam.  There are several reasons this may happen.  The first is that particular email may have looked like spam.  The more likely reason is that your domain is on a domain blacklist of some sort.  You can check for blacklisting at
Let us know the domain you are sending from and we'll try to help.

Author Comment

ID: 20423610
I purchase symantec Enterprise for my mail exchange server, I also have the spam premium installed.
I'm not sure why this is happening.  I did go to the link above and got this from spamcop.  I can dlist it but I want to make sure the server is OK.  Is it just a network problem with my ISP? listed in (

If there are no reports of ongoing objectionable email from this system it will be delisted automatically in a short time.

Causes of listing
SpamCop users have reported system as a source of spam less than 10 times in the past week
Automatic delisting
If you are the administrator of and you are sure it will not be the subject of any more reports of spam, you may cause the system to be delisted without waiting for us to review the issue.
You may only do this once per IP! So please be sure that the problem is really and truly resolved. If you delist your system and we get more spam reports about it, you will not be allowed to expedite delisting again. Delisting normally occurs 24 hours after spam reports have ceased.

You must be able to receive mail at one of the addresses below. Until you have received and confirmed your request, it will not take effect.

Looking for potential administrative email addresses for

Cannot find an MX for
Cannot find an MX for is an MX ( 40 ) for bounces (41 sent : 35 bounces)


Expert Comment

ID: 20423672
The way Spamcop works is that people report your domain as spam.  Either someone got into your Exchange server and sent out spam, or you just got reported a few times.  Check to make sure your Exchange server isn't set as an open relay, and secure as it can be, and then request it to be delisted.  Here is some information on checking to see if your Exchange server is an open relay:

The above link is for Small Business server, but the Open Relay works for Exchange 2003 (any version)  
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Author Comment

ID: 20424137
Thanks for the link.  I did check my email server and it is not relaying.  I am running symantec enterprise for exchange and corporate for the server.  All seems OK with  the server.  I staff person a few days ago brought over a heavily infected notebook.  Since my server and notebook are behind a firewall running NAT.  Well it looks like that system was acting as my email server.  I'm checking everything out and I'm going to request a delist of my server.  Ouch!

Author Closing Comment

ID: 31413309
thanks so much.  I found a DNS issue with my ISP where they needed to do a reverse DNS to my email servers.  Once I did that the blacklist started to clear up.  All is working.  I checked my systems for viruses and also the exchange data.  I also verified that my email server is not relaying.  All is well.  Thanks,

Expert Comment

ID: 20425161
Good luck!  They usually go through decently quick.  Update us on the status.

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