exchange 2003  and outgoing blocked to a specific domain

hello

setup
exchange 2003
half the users on exchange the other half using pop to ISP for mail
all using the same domain name
pop connectors goes to ISP to get mail forthe exchange server.

all mail has been moving fine until last week when the isp applied some new smtp security measures
now the exchange server is able to send mail out to all other doamins except
the users still suing POP withe same domain name.

Is there a way to setup a rule or something that would send a username & password authentication
for a specific domain?

thank you

Start Free Trial