We recommend that you create a test mailbox in %BRAND_OFFICE_365_SHORT% to test the hybrid environment you've set up. You ...

We recommend that you create a test mailbox in %BRAND_OFFICE_365_SHORT% to test the hybrid environment you've set up. You can create the mailbox on an on-premises %BRAND_EXCHANGE_ONLINE_SHORT% server using the %BRAND_OFFICE_365_SHORT% Mailbox wizard. If you want to create more than one test mailbox, you'll have to use this wizard for each test mailbox.