ESA Split Domain

[michaeltabler]

Greetings,

Is there a way for the ESA C670 to handle splitting mail delivery for a single domain to two different mail systems? (Similar to an Exchange 2010 Internal Relay domain)

We are in the process of merging our on-prem Exchange with a cloud hosted system (no federation).  The idea is to swing the MX record to the on-prem, accept inbound email on the ESA, then filter via recipient (those who have been migrated land on the on-prem Exchange servers - those that have not been migrated get forwarded to the cloud provider).  We can do this on the on-prem Exchange server, but that means ingress through the ESA to the Exchange, then back out the ESA...seems like it would be easier to handle the routing on the ESA.

Thanks!!

MT

[Mathew Huynh]

Hello michael,

This seems like a setup of incoming mail policies, where the users which are migrated (perhaps within an LDAP group?) to be matching against a content filter where you specify the mail host to deliver to, which could be your cloud mail host.

While the others will go through another policy (default?) and deliver to the SMTP route (on-prem).

So you accept for one domain via RAT.

But depending on policy matching, it will route based on the content filter that specified the other host, or your SMTP routes which goes to on-prem (or other way around).

Else you could possibly also use LDAP routing, where the LDAP routing query will send out, if it matches, you can specify the alternate mail host to deliver, so if the cloud/on-prem has a routing attribute defined, you can make use of this.

Regards,

Matthew

[michaeltabler]

Hi Mathew, 

Thanks for the suggestion.  I think I am going to try using the LDAP filter to search for membership in a DL - to differentiate those individuals who have been migrated vs those that have not.  It's a bit manual to keep up the membership of the DL through the migration process, but I think it will be easier that trying to put further logic into the routing.

The filter I am going to set up will be if the user is in the DL, then their message will be immediately routed to the cloud provider for delivery.

I am going to set this up with a few test accounts and post back the results.