Email to a specific domain bounces back

[SnoopFrogg]

I am able to receive email from users in the wananchi.com domain but cannot send to them (the email bounces back). I checked my SMTP logs and do not understand the 550 errors I'm receiving:

03/01/06 16:49:22 [3688:4792] __CheckReplyMultiLine():Reply from socket(2924) is: 550-Verification failed for <me@mydomain.com>

03/01/06 16:49:22 [3688:4792] __CheckReplyMultiLine():Reply from socket(2924) is: 550-Previous (cached) callout verification failure

03/01/06 16:49:22 [3688:4792] __CheckReplyMultiLine():Reply from socket(2924) is: 550 Unroutable sender address

03/01/06 16:49:22 [3688:4792] __CheckReplyMultiLine():Reply from socket(2924) is: 503 valid RCPT command must precede DATA

03/01/06 16:49:22 [3688:4792] SendEMailToDestination non of the recipients was accepted
03/01/06 16:49:22 [3688:4792] Sending 'QUIT'
03/01/06 16:49:23 [3688:4792] __CheckReplyMultiLine():Reply from socket(2924) is: 221 ns2.wananchi.com closing connection

When I telnet to the wananchi.com mail server, I receive the following output initially.

220-xserve.wananchi.com ESMTP Exim 4.60 #1
220-Fri, 03 Mar 2006 19:53:37 +0300
220-
220-This server uses various blacklist services to
220-filter mail from known spamming hosts & users.
220 See the Spam Advisory section at [URL unfurl="true"]www.spews.org[/URL] for more information.

Several Google search results I've gotten associate this error with Exim Mail. Is there something I can do on my Exchange 2K3 box to solve this problem?

[purple]
SnoopFrogg
MCSA+Security - Windows Server 2003
[/purple]

 

[Zelandakh]

Do you have a dynamic IP by any chance? If so, they deny all dynamic IP based mail servers. If you do not, see if you are on a DNS blacklist.

You may have a problem caused by your ISP reverse DNS too.

 

[58sniper]

Zelandakh's right. You're likely blacklisted somewhere. Goto

http://www.dnsstuff.com/

and run the spam database lookup using your IP address.

Pat Richard, MCSE(2) MCSA:Messaging, CNA(2)

 

[SnoopFrogg]

Thanks for the replies.

I have a static IP.

I searched several RBLs but I'm not listed. The wananchi.com domain is listed on a couple of RBLs. Also, I've run a DNS report on both our domains- my domain has minor problems while their's has several significant issues.

[purple]
SnoopFrogg
MCSA+Security - Windows Server 2003
[/purple]

 

[TechyMcSe2k]

They may have an internal spam filter. Contact their IT department to get your domain name "whitelisted

 

[WhoKilledKenny]

Some mail systems are set up to do a reverse DNS lookup on domains sending mail. This is a step to garantee that mail is coming from a ligit domain. If the reverse lookup fails mail is rejected. Test a reverse lookup using your domain.

 

[SnoopFrogg]

I ran a test reverse lookup on my IP as well as the IP for wananchi.com and we both have PTR records. When I go to dnsstuff.com and send a test email to an address in the wananchi.com domain, though, the test fails. I'll notify them.

[purple]
SnoopFrogg
MCSA+Security - Windows Server 2003
[/purple]

 

[58sniper]

WhoKilledKenny - the RFC states that you can't deny receiving the email message based solely on a rDNS failure. So if they are doing that, it needs to be pointed out to them.

Pat Richard, MCSE(2) MCSA:Messaging, CNA(2)