Export From O365
Office 365 to PST
Your own mailbox with no admin rights, or every mailbox in the tenant once an administrator approves. One .pst per mailbox, with online archives as separate files if you want them.
Needs desktop Outlook
ShareMaster V2
Office 365 email migration between tenants, out to PST, and back in
Copy mailboxes from one Office 365 tenant to another with their online archives, export them to .pst files on your own machine, or bring old PST, IMAP and POP3 mail into Office 365. It runs on Windows, talks to each mail service directly, and finishes every run with a report that says exactly what moved.
Availability. Email migration ships in the ShareMaster V2 beta, on the Email Tools menu. Any ShareMaster account can install the beta from the members area; the email routes run with a Clone Master licence or during the 14-day trial.
Three routes
Out, across, or in
Each route is its own tile on the Email Tools menu. The tile name is shown above each one.
O365 → O365
Tenant to tenant
Sign into both tenants, match each source mailbox to its destination, and copy. User mailboxes, shared mailboxes, online archives and Microsoft 365 group mailboxes.
No Outlook neededImport to O365
PST, IMAP or POP3 into Office 365
Old .pst files from a laptop or a file share, or mail sitting on any IMAP or POP3 server, brought into Office 365 mailboxes where people can search it.
Outlook only for the PST source
How it works
Four steps, the same on every route
No PowerShell to paste, no mailbox export requests to queue in a portal, and nothing to install on the mail server.
Pick the route
Export, tenant to tenant, or import, from the Email Tools menu. The tile tells you up front whether it needs Outlook.
Sign in
Sign into the source and the destination. Where a route needs more than an ordinary sign-in, the screen says what it is asking for and why before anything is approved.
Match the mailboxes
Source mailboxes are matched to destinations by address automatically. Fix the odd one by hand, leave any out, send one into a folder of its own, or create the destination as you go.
Run, then read the report
Live progress per mailbox and per message while it runs. At the end, a summary you can trust and an Excel report you can keep.
Read this before you plan
What moves, and what stays behind
Read the right-hand column before you plan a cutover. Each line is a current limit of the product, stated plainly.
Moves
- Mail, and the folder structure it sits in
- Sent and received dates, read or unread state, the sender and every recipient
- Ordinary file attachments, with their original file names
- Online archives, as rows of their own, into an archive the destination already has or one ShareMaster switches on
- Shared mailboxes, and Microsoft 365 group mailboxes when the move is tenant to tenant
Does not, yet
- Calendars, contacts, tasks and notes. Every route moves mail only, for now
- Inbox rules, mailbox permissions and delegates
- Emails attached to other emails, on any route that reads or writes a .pst file, and images placed inside the body of a message when exporting to a .pst. Ordinary file attachments are not affected
- Duplicate protection across separate runs. Resume skips what was already copied; starting the same migration again from scratch copies it all a second time
- Mail from an IMAP or POP3 server that only offers modern sign-in. Those sources take a username and password
The parts that usually go wrong
Built for a long run on a big tenant
Destination mailboxes made for you
Pick Create new mailbox in the matching grid and choose its licence and usage location, or create a licence-free shared mailbox instead. Online archives can be switched on as they are created, and a source mailbox over 50 GB turns that on by default.
Dates checked before the first write
When the destination is written over IMAP, ShareMaster first tests whether the received date will survive. If the test says it will not, you are told before a single message is copied, and you choose whether to carry on.
Throttling waited out
Microsoft 365 slows down large copies on purpose. Those responses are honoured as a wait, not counted as failures, and a dropped network connection pauses the run until it comes back.
Stop now, finish later
Cancel offers to finish what is in flight or stop straight away. Either way the run is in the history list, and Resume carries on from where it stopped without copying a message twice.
PST files that stay usable
One .pst per mailbox, named after the mailbox. Outlook caps a .pst at roughly 50 GB, so a bigger mailbox rolls over to a numbered second file at about 45 GB instead of failing halfway. The .pst is re-opened and counted when the export ends.
A report that does not round up
Every message has a row: mailbox, folder, size, and whether it was copied, skipped or failed. A run that falls short is called incomplete on the finish screen, not described as done. Reports stay downloadable from the history for 90 days.
Requirements
What each route needs
| Every route | A Windows 10 or 11 machine running the ShareMaster V2 beta, and a Clone Master licence or trial. |
|---|---|
| Export your own mailbox | Your own sign-in, and desktop Outlook 2016 or newer installed and closed. Exporting your online archive too also needs Outlook signed into the same tenant. |
| Export the whole tenant | A Global Administrator to approve a one-time consent that lets ShareMaster read mail. Other users' online archives are read through your Outlook, so ShareMaster uses an Exchange admin permission it sets up for you to give your account Full Access to those mailboxes first. That is a change in the source tenant, and it can take up to an hour to reach Outlook. |
| Tenant to tenant | A sign-in to each tenant. Online archives, group mailboxes and creating mailboxes each need a one-time admin consent, in both tenants where it applies; the screen asks only when you use that option. |
| PST import | Desktop Outlook installed. The .pst files are opened read-only and never changed. |
| IMAP or POP3 import | The server name, port, username and password, an app password where the host insists on one. One source account per run. |
Step-by-step instructions for every route are in the ShareMaster email migration guide.
FAQ
Office 365 email migration, common questions
Can I export an Office 365 mailbox to PST without admin rights?
Yes, your own. Choose My mailbox, sign in as yourself and pick a folder on your machine. Your mail is written to a .pst file there, and you can tick a box to export your online archive to a second .pst as well. Exporting other people's mailboxes needs an administrator.
How do I export every mailbox in the tenant?
Choose Other mailboxes and sign in as an administrator. A Global Administrator approves a one-time consent that lets ShareMaster read mail, and every mailbox in the tenant is then listed for you to tick. Each one is exported to its own .pst file named after the mailbox.
Do I need Outlook installed?
Only for the routes that touch a .pst file: exporting to PST and importing from PST. A .pst can only be written or read through Outlook, so it needs the desktop Outlook, 2016 or newer, and not the new Outlook from the Microsoft Store. Close Outlook before an export, because ShareMaster runs its own copy in the background. Tenant to tenant, IMAP and POP3 imports do not use Outlook at all.
Can it migrate online archives between tenants?
Yes. Turn on Look for online archives when you sign into the source and each archive is listed as a row of its own, next to the mailbox it belongs to. You decide where it lands: an existing archive, the archive of a new mailbox, or a shared mailbox's archive. ShareMaster can switch on the destination archive for you.
Does it migrate calendars and contacts?
No. Today every route moves mail and the folders it sits in. Calendars, contacts, tasks and notes stay in the source, so plan to move those another way.
Can it create the destination mailboxes?
Yes. While matching mailboxes you can create a new licensed mailbox, with the licence and usage location you choose, or a licence-free shared mailbox, and either one can have its online archive switched on as it is created. Creating mailboxes needs a one-time admin consent in the destination tenant.
What happens if a migration stops partway?
Open the run from the email migration history and choose Resume. It reconnects to both sides and skips every message already copied. It must resume into the same destination account it started with. Starting a brand new run instead copies everything again, so use Resume rather than re-running.
How do I know nothing went missing?
Every run ends with a summary that says plainly whether it finished, finished with failed messages, or stopped early, and an Excel report lists every message with its folder, size and status. After a PST export ShareMaster also re-opens the .pst and counts what is inside against what it copied, and warns you if the file holds fewer items.
Can I bring in mail from an old host or an old PST file?
Yes. Point it at any IMAP or POP3 server with a username and password, or add one or more .pst files, and map each one to an Office 365 mailbox. The source is only read. An IMAP or POP3 import moves one source account per run, and POP3 can only see the inbox.
Which licence includes it?
Clone Master, the same tier as SharePoint migration. The 14-day trial reaches it too.
Move your mail with a report you can check
14-day free trial. No credit card. Your mail travels between your machine and the mail services, never through us.