Cause:
Customers would like to change their hosted or on premise mail server to point to office 365 and would like to reduce the impact of mail interruption.
Solution:
This document will focus on the steps to perform so that the users don't suffer from mail interruption while the move is in process.
so before you start doing anything on the other side you must:
1- Login to your Proofpoint portal
2- To assure Email continuity, all users on proofpoint portal must be set as End Users, make sure they are all able to login to the portal. If this is not the case then:
- Make sure all the users are set as "End Users"
- If not select ALL the users
- MASS UPDATE USERS button
- Chose "End User" in the drop down menu next to "Role"
- Click on "Update users" button. (screen shots below)
3- Advise users that they can login to the portal using the link <same as the one you, admin, is using to login> you will provide in the email
4- Require Users to change their Password
5- Let know Users to use their Emergency Mailbox
5- Navigate to Account management > Domains and Change the "Primary Delivery Destination" to point to a non valid IP i.e. 10.10.10.10 (screen shot below) this way all messages will be held on the Proofpoint server. Screen shot1
6- Wait for 1 hour for the change to propagate otherwise you might experience some bounce messages
