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I'm having problem with one of my target email recipient, when I tried to send email to, I got this error message from my email server:

Diagnostic information for administrators:

Generating server: #< #5.0.0 smtp; 554 "Refused. You have no reverse DNS entry. Contact for details."> #SMTP#

which PTR records should I add into my intenral DNS or my ISP DNS server ?

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up vote 3 down vote accepted

Your ISP needs to add the reverse PTR for your mail server. Just call them up and explain you need a "Reverse DNS Entry", they'll just need to know what your mail server's DNS name is (say and they should be able to take care of it*.

Note: This assumes you have the mail server setup correctly otherwise and forward DNS working correctly as well (ex, globally resolves to

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ah so in this case the PTR records should be to match up to the name used by my mail server ? – Server System Specialist Nov 23 '10 at 3:59

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