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

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.
           

He was e-mailing [email protected]

When looking at the mx record I saw the following.

5 smtp.perimeterco.com 63.76.208.166 86400  
6 smtp2.perimeterco.com 63.76.208.238 86400  
7 mailhost.eastriverbank.com 66.253.6.82 86400  
10 mail28.ixwebhosting.com 76.162.254.116 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.

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

I used the following website
http://www.dnscolos.com/free-dns-report.html