Question : Problem with Relaying mail to internet  in Exchange Server 2007 with 3 Accepted domains

Hi Experts
I  had configured my exchange before 1 yr to receive emails for 3 domains that belogs to our group.  Everything working fine through out this year. Recently we are having issues with ip blacklisting and geting NDR messages for one of the domain saying your IP has been black listed visit ://bsn.borderware.com ..............   for  more details etc.

Details of may MX configuration and relay ip.
first domain : preference 10 mail.companya.com and  PTR to a.b.c.114
Second domain: preference 10  mail.companyb.com PTR to a.b.c.115
Third domain: preference 10 mail.conpanyc.com PTR to a.b.c.116
SMTP Communication to this 3 IP are nated to my Barracuda spam firewall box located in DMZ.
Send Connector configuration:
My exchange  is configured to send mail directly to internet and and it is configured to use the public ip a.b.c.114.. The originating ip adress of  this three email domains ip is  a.b.c.114.
Kindly advise how I can configure a proper relay for this 3 domains and to avoid chances to get blacklisted? or do I need to make change in MX ? if required how?

Answer : Problem with Relaying mail to internet  in Exchange Server 2007 with 3 Accepted domains

yes they will.

check this.

http://www.amset.info/exchange/dnsconfig.asp

Going to bed man..its really late :-(

Please post your queries here - I will check in the morning.