exchange error 553. Unable to verify address

[soportesinaki]

Dear Sirs,

Some weeks ago we migrated the mail services from our ISP to our Exchange 2003 server. It have been working OK and we can send mails almost everywhere.

But this week we have found a problem sending mail to one address. Our server gives back an error "error 553, unable to verify address". It looks like they try to verify our sending address, without success.

The destination address works ok, we have tried sending mail from gmail and they reach the destination without problems.

What could be working wrong?

Thank you for your help!

Best regards,
iñaki

 

[liorz66]

It could be PTR record. the destination server checks if your source IP has PTR record (DNS-reverse lookup). since you probably don't have it you get this error message

 

[soportesinaki]

Hi,

Could it work if I created an A Record at the public DNSs pointing to our public IP with our servers name (ourserver.ourdomain.com) so they can see they point to the same IP?

Thank you!
iñaki

 

[liorz66]

no
it must be PTR record:
the "real" IP address backwords see example for mail.yahoo.com 64.156.215.8

8.215.156.64.in-addr.arpa name = mta-5.level3.mail.yahoo.com