Mail are being rejected by one remote mail server

[GSRRGS]

I have qmail-1.03 along with qmail-scanner-1.25st and spamassassin-2.60.

Till now everything was working fine but recently after one of our client complained, I noticed that mails to particular domains are being rejected with following error in /var/log/maillog file:

Sep 15 04:06:34 devis qmail: 1126736494.491801 delivery 6597: deferral: Connected_to_202.79.33.170_but_my_name
_was_rejected./Remote_host_said:_551_Verification_of_sending_machine_failed:_no_mail_will_be_accepted/

Mails to other domains are going without any problem.

Immediate help is needed.

Thanks in advance

 

[thedaver]

With technical enforcement of RFCs that describe the full breadth of implementing a mail server, one of the first things to go bad (which creates a situation where the receiver refuses a sender's connection) is that there is no reverse DNS published for your mail server.

Please check that.

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[GSRRGS]

The problem is not related to reverse DNS entry. My mail server has reverse DNS entry

 

[thedaver]

OK, if your reverse DNS is complete including mail. or whatever your MX says,

THEN

you may be subject a cadre of other server validation filters such as SPF and other bolt-ons. You're going to need to contact that administrator and have them tell you why your server is rejected.

You might be blacklisted by a spamhaus too

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[GSRRGS]

Yes, I have written to the administrator from my other email account and waiting there reply. Also tried to call them but was not available on phone. Anyway I'll followup the matter with them and will post the result.

Thanks for answering my queries.

 

[GSRRGS]

The problem has been solved. One of their mail server was having misconfigured and rejecting mails from our domain. It has been resolved now.

thnx