If you’re used to using an on premise Exchange server you’ve probably run the Export-Mailbox command to archive a mailbox now and again. Unfortunately, there is no officially supported method for exporting mailbox contents in Office 365 to PST via powershell. However, there are some good work around methods.
in-place eDiscovery & hold
You can use the in-place eDiscovery & hold tool to create a hold on a mailbox and then export those contents PST. This is good for the one-off mailboxes and the process is pretty easy. The only caveat is that the mailbox in question must have an E3 license.
Log in to the Office 365 Admin panel and go to Exchange Admin > compliance management > in-place eDiscovery & hold.
Click the plus sign to create a new hold and walk through the wizard.
- Give it a name
- Specify mailbox to search
- Include all content
- Place content matching the search query in selected mailboxes on hold and Hold indefinitely
Give the hold some time to run and discover all the messages in the mailbox – depending on the size of the mailbox this could be a few hours. Once email discovery is complete there will be an option on the toolbar at the top of the in-place eDiscovery & hold page to export the contents of the hold to PST.
Third party tools
For an automated exporting of multiple mailboxes you will have to utilize a third-party tool. I’ve personally used the Office 365 Exchange Migration Tool by Message Ops to export around 200 mailboxes to PST from single Office 365 tenant. I haven’t yet found another tool that performs the same function.
Let me know in the comments if I’ve missed a method of exporting or if there is a third-party tool you’d recommend.