Question : Remote delivery for email address in local delivery domain

There's an exchange server that sends and collects emails from ISP for somedomain.com by pop & smtp connector - because internal email traffic is very intense I set up a local delivery on exchange for somedomain.com so only emails for remote domains are being relayed to ISP smtp server.

Now, there are new users (outside users) that have accounts on ISP server within somedomain.com but they don't work in office and they will never do. The problem is "office" users can't send emails because exchange treats everything sent to somedomain.com as local delivery and it obviously fails.

Is there any way to set up exception for SMTP server for specific email accounts to relay them to remote smtp server? I'm trying to avoid setting up AD accounts for "outside users".

thanks
Rob

Answer : Remote delivery for email address in local delivery domain

you need to adjust your Recipient Policy for that domain

uncheck the 'This Exchange org is responsible for all email delivery to this domain' under the smtp namespace properties in your RP

create a external SMTP connector for that namespace that forwards all unresolved mail to that domain upstream to your isp

just be careful you don't have any rules/forwards/etc that  can cause a mail loop