Throttling and Blocking Email from Persistently Vulnerable Exchange Servers to Exchange Online

Hi Team, The_Exchange_Team KevinShaughnessy ScottSchnoll 

I hope this message finds you well. I am reaching out to seek clarification on the potential impacts related to throttling and blocking in the context of an upcoming upgrade in our Exchange Server environment.

Our Current Environment comprises the following components:

1. Exchange 2010 Edge Server
2. Exchange 2013 CAS Server
3. Exchange 2013 MBX Server

The proposed upgrade involves only the Exchange 2010 Edge Server, which will be upgraded to Exchange 2019. The Exchange 2013 CAS and MBX servers will remain unchanged in this process.

I am particularly interested in understanding the potential implications on throttling and blocking when relaying emails internally from the 2013 MBX server to the upgraded Edge Server and subsequently to Microsoft 365. Considering that the direct connection to Microsoft 365 will be facilitated by the upgraded Edge Server:

1. Will this upgrade effectively address throttling and blocking concerns for direct connections to Microsoft 365 through the Edge Server?

2. Should we anticipate any throttling or blocking impacts for internally relayed emails, specifically starting from the 2013 schedule, and passing through the 2013 MBX server to the upgraded Edge Server before reaching Microsoft 365?

I would greatly appreciate your insights on this matter and any recommendations you may have for ensuring a smooth transition with minimal disruptions.

Thank you for your time and assistance.

Best regards,

Janak Khadka