Exchange Online Migration - Customers already with ExOL

Smaller Sized Mailboxes

This is for customers who already had an Exchange Online mailbox containing fewer than 60,000 items.

At the end of the working week of your department’s migration you will receive an email notifying you that the process of moving your mailbox has begun. At that point you will use https://outlook.office.com to send and receive email.  You will eventually need to change all of your devices to point to that system but can use webmail in the meanwhile.  Your email will be copied into this mailbox over the weekend.

Important: don’t change anything yet - you need to continue to use your Medschl setup until you are advised that your mailbox has been migrated!

Because of the larger amounts of data yet to be transferred, we may select your mailbox to be pre-staged of the number of items. It would mean the below process for large mailboxes would be followed.

Unfortunately it is not possible for you to easily determine the number of items in your mailbox. If you do have your mailbox pre-staged you’ll only know because you have historical email items appearing in your Exchange Online mailbox prior to the end of the week. Should this be the case, please follow the points to note section at the end of this page.

Here is the schedule of migration dates for the remaining departments: ​https://cscs-itsupport.atlassian.net/wiki/spaces/FAQ/pages/274858085 .

Larger Sized Mailboxes

If you already have Exchange Online and your mailbox has more than 60,000 items, your migration will happen in 2 parts.

Part One : A snapshot will be taken of all the items in your mailbox and then we will begin to move all historical email into Exchange Online. During this period if you were to log into Exchange Online mailbox, you would notice older email now being populated in Exchange Online.  You would continue to use your Medschl setup at this point.

Part One will begin running at the start of the working week.

Part Two : The migration tool will run again at the end of the working week and copy in anything created or received since the first snapshot.

A few points to note:

  • Do not start using your Exchange Online mailbox to send Medschl email until you have been advised that your mailbox has been migrated. You can only send email from your @cam address during the pre-stage period.

  • Do not do anything with any historical messages that are copied over to Exchange Online such as delete or reorganise them. The risk of doing so could result in messages reappearing where they were originally thus creating duplicates. You would not lose any email but create extra work for yourself to tidy the duplicates.

  • It is safe to delete or move any emails created or received in the past 12 months within your Medschl mailbox prior to the end of week mailbox move.

What is Pre-Staging?

Pre-Staging means that some data from a mailbox is copied to Exchange Online in advance of the migration. This is meant to give CSCS a head start on copying the data thus reducing the amount of time the actual migration will take over your department’s designated weekend.