problem of sending out emails through sendmail -- error code 421

kkeith · 06-29-2006, 09:36 PM

Hi all,

I have the following problem in sending email out, but only for 1 or 2 receiptents, there're no problem for the others. Plesae help me to solve this problem as I don;t know whether it's the problem of our email server settings or the receiver's.

THanks
Keith

----- Transcript of session follows -----
... while talking to mailin-01.mx.aol.com.:

>>>>>> DATA

<<< 421-: (DNS:NR) http://postmaster.info.aol.com/errors/421dnsnr.html
<<< 421 SERVICE NOT AVAILABLE
... while talking to mailin-02.mx.aol.com.:

>>>>>> DATA

<<< 421-: (DNS:NR) http://postmaster.info.aol.com/errors/421dnsnr.html
<<< 421 SERVICE NOT AVAILABLE
... while talking to mailin-03.mx.aol.com.:

>>>>>> DATA

<<< 421-: (DNS:NR) http://postmaster.info.aol.com/errors/421dnsnr.html
<<< 421 SERVICE NOT AVAILABLE
... while talking to mailin-04.mx.aol.com.:

>>>>>> DATA

<<< 421-: (DNS:NR) http://postmaster.info.aol.com/errors/421dnsnr.html
<<< 421 SERVICE NOT AVAILABLE

bathory · 06-30-2006, 04:59 AM

If you follow the link provided by aol (http://postmaster.info.aol.com/errors/421dnsnr.html), you'll see that this is caused because your mail server does not have a reverse dns record. There are also suggested solutions there.

Regards