Question : SMTP 554 Client host rejected

Hello all,

I am encountering an email issue with one of our employees. It is when he sends an email to a company (lets call it xyz) He has tried multiple contacts in the company (we know they are accurate). However the emails bounce back immediately with the following error.

Any thoughts? I had our ISP change our pointer record so a reverse lookup is now the correct dns entry...

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Your message did not reach some or all of the intended recipients.
 
      Subject:	Our Employee - New contact information
      Sent:	9/3/2009 1:19 PM
 
The following recipient(s) cannot be reached:
 
      [email protected] on 9/3/2009 1:19 PM
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            : Client host rejected: Use your providers mailgateway 20060811>

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Answer : SMTP 554 Client host rejected

If someone is using Postini, the tools on dnsstuff.com are useless for confirming behaviour on outbound email, because they cannot test for that.

Note that the error above is for 75.144.198.237, whereas you have posted in a second message that you tested 75.144.198.235.

I do an nslookup on 75.144.198.235 I get the result you are expecting.

Therefore if your email is supposed to be going out on 235 then you need to check your NAT.

Simon.