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NDR, Your mail system could not find a way to successfully communicate with the destination system

Posted on 2009-02-18
Medium Priority
Last Modified: 2012-05-06
I just need to confirm what I am think since this I am only at mid level with exchange.  I have an invidual that here that sent and e-mail message that he was able to send to before that received and NDR that states.  

External} on 2/17/2009 5:12 PM
            Your mail system could not find a way to successfully communicate with the destination system. Please notify your administrator.
            <FS-Mail.ERB.local #5.5.2 smtp;502 5.5.2 Error: command not recognized>

He was e-mailing user@eastriverbank.com

When looking at the mx record I saw the following.

5 smtp.perimeterco.com 86400  
6 smtp2.perimeterco.com 86400  
7 mailhost.eastriverbank.com 86400  
10 mail28.ixwebhosting.com 86400  

I tried telneting into each one to test but couldnt even get a helo response.  The mailhost.eastriverbank.com doesnt even seem to exist.

Any and all help is appreciated.
Question by:dplaw
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LVL 18

Expert Comment

ID: 23672184
can you try re-send? I just checked the mx records, at least the last one is accepting emails.

Author Comment

ID: 23672215
So it does appear that the top weighted 3 are not accepting e-mailsat this time correct?  How did you verify that the last one is accepting at this time?  And yes, I will ask the user to try again.
LVL 18

Accepted Solution

flyingsky earned 1600 total points
ID: 23672327
I used the following website

Author Comment

ID: 23672395
Thank you.  Just a quick follow up question, it mentions that it may be greylisting, how does that effect my domain and the one your ran the test from and what does it mean?
LVL 18

Assisted Solution

flyingsky earned 1600 total points
ID: 23672867
greylisting is a way to fight spam. it means
"A mail transfer agent (MTA) using greylisting will "temporarily reject" any email from a sender it does not recognize. If the mail is legitimate, the originating server will try again and the email is accepted. If the mail is from a spammer it will probably not be retried since a spammer goes through thousands of email addresses and can not afford the time delay to retry."

Your server should retry if the first try failed, then if the recipient's email think it's legetimate, it will receive.

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