I need assistance with an issue I am having in sending email to an external domain.
A few months ago the company I work for created another, smaller company with a different domain name. The decision was made by management at that time to host the email boxes for that company on our Exchange 2010 server. I created a new accepted domain in the Hub configuration on our mail server, and a new email address policy for those users and created the mailboxes. The mailboxes created for these users on our mail server have been working fine.
Recently, due to some other considerations, the decision was made to move those mailboxes to an external hosting provider. I set up the mailboxes for those users at the hosting provider, and this past Saturday made the DNS zone changes to route email to the hosting provider instead of to our Exchange server. After some testing on Saturday I determined that email sent from other outside addresses was being delivered correctly to the mailboxes at the hosting provider but email sent from our internal addresses was still being delivered to the old mailboxes on our server. I assumed this was because the accepted domain was still in place on our internal Exchange server, and opted to leave that in place over the weekend.
This morning during some further testing, I removed the address policy and the accepted domain on the Exchange server for the second company, expecting that email sent from addresses in our primary company would then be routed to the mailboxes at the hosting provider. What I am instead seeing is that email is still being delivered to the mailboxes that reside on our Exchange server. As a test, I disabled one of those email boxes and attempted to send an email to that person, and recieved a non delivery message from our Exchange server.
As the email for the domain name of this second company is now being hosted outside of our Exchange organization, and the correct DNS records are in place, I expected email sent from our primary addresses to be routed to the external hosts just as if we were sending email to any other external domain. That is not what I am seeing, however. As an aside, the Internet send connector on our Exchange server is set to use DNS MX records to route mail, and also to use external DNS lookup settings on the transport server. Because of this, I added external DNS servers to the NIC configuration on our mail server, to no avail.
What do I need to do to ensure that email sent from addresses / accounts on our internal server are routed externally so that they are delivered to the mailboxes at the hosting provider going forward?
Thank you very much in advance,