When an account is migrated/transitioned to Office 365, a unique mail folder (named the same as the email address of a consolidated email address) is created in the Office 365 account which will contain every folder/email from the consolidated account.
Important: DO NOT START moving folders/mail until you receive a message for each account that is being consolidated telling you that the account has completed the migration process.
In the example below, Bucky Badger has two email accounts (email@example.com and firstname.lastname@example.org) which are being consolidated into one Office 365 account. Both contain email data. Note: To expand the folder structure for each account, click the left arrow next to the email address folder name.
In Outlook on the web, if you have not already, expand your folder list to show all folders. Once you've performed this step, your view will match the below image for what the mail screen will look like after the transition to Office 365.
As you can see, there are two unique folders created within his Office 365 account. A description of what you are seeing follows:
Note: To expand the folder structure for each account, click the left arrow next to the email address folder name. Clicking on the folder name will not expand or show any emails/folders.
Important: All new mail is arriving into the Inbox under the 'Bucky Badger' account.
You can organize e-mail messages, appointments, meetings, contacts, and tasks in your mailbox by moving or copying them. For complete details on how to manage folders, see:
Important: If you plan on restructuring your folders/emails, using Microsoft Outlook to connect to your account, we highly recommend performing this action within Outlook on the web prior to configuring and running Microsoft Outlook to reduce the impact of syncing your folders/emails within Outlook.
Remember, the folder names (email@example.com and firstname.lastname@example.org) you see are only names of each folder. They can be renamed to whatever you like. If you are okay with keeping things as they are, then there is no need to make any further changes. All you will need to do is think about how you want to restructure your main account folder list and any new mail arriving into your account (maybe by setting up some rules (filters)).
If you'd like to re-create rules (filters) in your accounts, please refer to the following documentation: Office 365 (Outlook on the web | Outlook for Windows/MacOS) - Using Inbox Rules