What migrates — and what doesn't
Eleven workloads under one license. The limits are stated here rather than discovered at cutover.
Exchange Online
Mail is migrated with folder structure preserved and verified per message.
| Workload | What’s included |
|---|---|
| User mailboxes | Mail, folder hierarchy, read state, attachments |
| Online archives | Full archive contents, migrated as a separate workload |
| Shared mailboxes | Contents plus proxy addresses |
| Distribution lists | Membership and proxy addresses |
| Calendars & contacts | Appointments, contacts and tasks |
| Inbox rules & settings | Rules, mailbox settings, out-of-officeRequires mailbox-settings consent |
Files
Content, structure and sharing intent — with version history to a depth you choose.
| Workload | What’s included |
|---|---|
| OneDrive for Business | Files, folders, version history |
| SharePoint sites | Document libraries, hierarchical permissions |
Teams & Groups
Migrated through the Microsoft Teams migration API, preserving message fidelity.
| Workload | What’s included |
|---|---|
| Microsoft 365 Groups | Membership, owners, visibility, mailbox |
| Teams channels | Messages with original timestamps and authors |
| Teams chats | 1:1 and group chat history |
| Teams files & owners | Channel files and team ownership |
Known limits, stated up front
These are constraints of the Microsoft APIs and of Exchange Online. Knowing them before you scope is worth more than a longer feature list.
Messages above 150 MB
Exchange Online will not accept them under any circumstances. Oversized items are reported as explicit skips rather than dropped silently.
Calendar and contact identity
These items get new internal identifiers at the destination. Content is preserved, but they cannot be matched one-to-one against source items the way mail can.
Meeting invitations
Historical meeting requests land as ordinary mail. Content and attachments are preserved; live invitation behaviour is not, because Exchange does not allow authoring a meeting message.
Recoverable and purged items
Only mail present in the mailbox is migrated. Items in the recoverable-items dumpster are not, and are excluded from coverage figures.
Folder placement under destination retention
A move-to-archive policy on the destination relocates old mail after it lands. The mail is present, but in the archive rather than the original folder, unless the policy is suspended during migration.