rcpthosts error 5.7.1

[licarse]

Hi,

Every now and then, when a specific user in my domain wants to send an email to a specific domain, he gets the following error:

---------------
recipient_address on 12/3/2009 3:40 PM
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<my_smtp_server #5.5.0 smtp;553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1)>
---------------

If I try to send an email to those recipients, I don't get the error.

What should I check on my side? I'm running Exchange 2003 on a 2003 Server, XP Pro Clients using Outlook 2003. I'm not an Exchange expert, so details on procedures will be mostly appreciated.

 

[FireMike84]

llcarse,

There are a few different things that can cause this issue within an exchange setting and the biggest one appears to be how your email server is setup through your ISP. Some ISP require all your email be setup to be sent through them to help remove spammers. Check out this link on another post that talks about this issue.

http://forums.msexchange.org/m_150274600/mpage_1/key_/tm.htm#150274611

Mike Walton
Network+ CCENT
New Technology Articles

http://www.mikenetpc.com

 

[licarse]

Thanks Mike. I will check the post and let you know the result.

 

[licarse]

Mike,

I checked the solutions proposed but none of them applied to me. I'm seriously thinking that it may be antispam software on the recipient's side, but I have no way to check that out.

 

[cmeagan656]

The bounce message states:

that domain isn't in my list of allowed rcpthosts (#5.7.1)>

but you can send to those recipients. That would lead me to believe the issue is on your end.


Have you checked the e-mail profile set-up of the user with the problem? Is everything set-up the same as yours?

Hope this helps.

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[Treyze]

Hi,

I'm going to put in my $.02. The spam server on the other end may be checking for a reverse DNS entry to see if you are a valid domain. Since you are not on their list, you are denied delivery.You can contact your ISP and put a reverse DNS entry on their public DNS server do that your domain is valid.

-E

 

[cmeagan656]

The spam server on the other end may be checking for a reverse DNS entry to see if you are a valid domain.

That doesn't explain why licarse can send from the same domain to the same recipients that the other user is having problems sending to.

Hope this helps.

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[licarse]

cmeagan656,

Yes, the user's profile is set-up the same as mine and as every other user. Any other suggestion?

Is it possible to get this error if antispam software on the other side is rejecting some of this user's emails based subject words or some other specific conditions?

 

[cmeagan656]

It is possible that the mail is being blocked based on subject words or some other condition but usually that would apply to any e-mail being sent from your domain, not just from one specific user. I am assuming that when you tested sending an e-mail yourself you sent the exact same e-mail?

It is also possible that the anti-spam software on the other side is configured per user and the person that your user is trying to send to has your user blocked. Can your user send the same message to someone else in the problem domain.

Hope this helps.

Please help us help you. Read Tek-Tips posting polices before posting.

 

[licarse]

I forwarded the original email to the sysadmin and to one of the bouncing mailboxes on the other domain.

I'll try to send another email to the bouncing mailboxes from my user's account. Problem is I'm right now far away from the office and he's a difficult user, I can't ask him to do it just by email.

I'll return to my office the 21st and let you know if the email bounces back again. I still think the problem is in the other domain, but it's all a mess: The sysadmin knows nothing (technically speaking) and asks for help to HQ helpdesk (don't ask), HQ seems to know nothing too and say the trouble is in my domain! Although I asked them, they don't even bother checking their antispam log and letting me know if there's any blocking being applied to my domain.

 

[licarse]

cmeagan656,

I ran mxtoolbox to see what happens. The other domain has three mx servers, one of them replies with 553 5.7.1 when running the smtp test, and guess what? It has a 10 priority while the other two have 5.

So I guess it confirms me that the problem is on the other side... or not? Am I wrong? Any other thing to check?

 

[licarse]

cmeagan656,

BTW, I'm not an exchange/email expert. What should they do to fix this? I guess I'll have to give them the solution, otherwise I'm pretty sure they won't fix it.

 

[licarse]

My last post today: My best guess is that they have to whitelist our domain in their antispam software. I'll wait answers an opinions in this forum before sending them an email about this.