Im in the process of setting up the Exchange Online Protection but have come up with a query.

The install will be a pure standalone environment with all mailboxes being on-premise. I need the setup purely for spam/malware protection.

The question is do I need to add all the on-premise users into the Office 365 portal? The instructions tell me so but surely I can set the domain to be Internal Relay and they will forward on to the on-premise?

Thanks in advance

Hi,

Since this question is more about Exchange Online and Office 365, I suggest you post the question in Office 365 Community Forum:

http://community.office365.com/en-us/f/default.aspx

The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding.

In this current forum we mainly discuss questions and feedbacks about Office client products.

Regards,

Melon Chen
TechNet Community Support