Anyone who didn’t have an Exchange Online mailbox previously received an email from the IT Announcements mailbox titled ____ on 1 August 2023. If you received that message this applies to you.
Your ExOL mailbox was created for you a few weeks ago and all your old messages up to 30 June 2023 were copied into there.
For you the final part of the migration will begin on xxx date at yyy time. As of that time you will use https://outlook.office.com to send and receive email. You will eventually need to change all your devices to point to that system but can use webmail in the meanwhile. Any email created or received after 1 July 2023 will be copied into this mailbox over the weekend.