I manage a domain that is basically a sister domain to another organization (government entities). My domain looks like “sub.domain.gov” and the other domain is “domain.gov”. From a namespace perspective we look like a subdomain but we are not, we are separate domains with a trust setup between the two. They host email for us so here is my problem.

When we create users we have to wait for the other domain to create their mailbox on their Exchange server and link the mailbox to our user’s AD account. This can sometimes take days and sometimes weeks to accomplish which is frustrating for us and the user. We have our own Exchange server that we use during the initial user setup to send them a link to their annual security training, completely stupid I know. So once their main email is created we have to go back into the user profile and setup their actual email stuff for Outlook.

My question is, could this article potentially resolve this issue? I just want to create their account and setup their Outlook once and have it so if someone sends an email to “username@domain.gov” it will land in their mailbox at “username@sub.domain.gov”.

If this would work, how would setting this up affect the users setup the old stupid way? Thank you for your time reading this and hopefully it made some sense.

We have a centralized hybrid exchane environment. We use a local barracuda appliance and that is why we used centralized. We will eventually move all cloud but we need to resolve a few issues first. Historically we use our local cas as an smtp server for many of our applications SQL alerts PRTG alerts ect. We have one server that needs the ability to send email external support rather than an internal team but for some reason we are unable to get the mail to route out of our exchane server. Currently we send email from that server with an inbound connector that allows anonymous email sent from the server IP Address to the CAS. Any ideas as to how this can work?

Thanks Paul. Putting change in tonight. I’ve seen articles for the transport rules. I’ll get those in place when I make the change. Appreciate the feedback!

Yes, you’ll need to make the same configuration on the other side as well. Now you’ve got an infinite loop condition, so you also need to add transport/mail flow rules to each organization to set a custom header to enable loop conditions to be detected and stopped.

My Google skills have left for the weekend so hopefully you’re able to find an article explaining that in more detail.

Depends what you mean by “server”. Perhaps what you mean is “organization”? An Exchange organization can have multiple servers, that’s normal and it’s not SMTP namespace sharing.

SMTP namespace sharing can be configured between multiple organizations. More than two gets complicated.