3499 (000B09AA) Host unreachable Exchange 5.5

[kavita11]

I am getting the following NDR when I try to send email to some domains. rr.com in particular.


The recipient was unavailable to take delivery of the message
The MTS-ID of the original message is: c=US;a= ;p=MYDOMAIN;l=MYSERVERNAME -030424210339Z-312
MSEXCH:IMS:MYDOMAIN:Houston:MYSERVERNAME 3499 (000B09AA) Host unreachable.

I have 2 exchange 5.5 SP4 servers. One of them is outside the firewall and one inside the firewall. I have generic SMTP handler enabled on the RAPTOR firewall but the exchange server outside the firewall is also unable to send emails to rr.ccom so the firewall really does not matter.
I have checked my DNS settings on both Primary as well as secondary, I even have reverse lookup enabled. We are not blacklisted either but still the mail does not go out.

HELP, I am out of options....

Thanks
Kavita

 

[Vennie]

I am getting the following NDR when I try to send email to some domains. ?.com ( not all .com domains)

The recipient was unavailable to take delivery of the message
The MTS-ID of the original message is: c=US;a= ;p=MYDOMAIN;l=MYSERVERNAME -030508065256Z-707
MSEXCH:IMS:MYDOMAIN:MYSERVERNAME:MYSERVERNAME 3499(000B09AA) Host unreachable

I have SBS 4.5 SP 6a with exchange 5.5 SP 4 server.

Help
do you have a solution

Thanks!