Need help exporting Office 365 to PST for archive purposes

WilliamsWelsh — Sat, 11 Jul 2026 09:59:08 GMT

Our compliance team wants us to archive mailboxes for employees who've left the company over the past year — about 35 mailboxes total, all needs to go to PST for long-term storage. Never done this at this scale before, so looking for advice before I mess something up.

A few concerns I have:

Most of these accounts are already disabled or deleted, so I'm not sure the native Microsoft tools will even work
I don't want to babysit 35 individual exports manually
Archive means I need this to actually be complete and verifiable later, not just "probably fine"
We don't have E5 licensing across the board, so I'm not sure eDiscovery is even an option for all these mailboxes
From what I've read so far, eDiscovery Content Search can work for archiving but gets complicated fast with disabled accounts and licensing requirements. A few people in another thread mentioned dedicated export software handles this better since it's built for bulk jobs and doesn't care whether the account is active or not.
Was looking at this DRS Softech Office 365 to PST export tool since it seems to handle exactly this — bulk export including inactive accounts, with reporting so I can confirm everything actually made it into the PST files.

Re: Need help exporting Office 365 to PST for archive purposes

rowanfletcher — Tue, 14 Jul 2026 12:50:51 GMT

Exporting PST file is one of the most convenient options for archiving Office 365 mailbox data.
It’s easy to maintain a PST archive locally, open it in Outlook when needed, and maintain a separate copy of important emails for compliance or long-term retention.

1. Manual Method

Set up your Microsoft 365 account in Outlook
Wait for the mailbox to finish syncing
Outlook has the Import/Export option that exports the mailbox to a PST file.

Limitation: This works for individual mailboxes, but exporting large mailboxes can take quite a while. In the case of archiving multiple Office 365 accounts, it becomes tough to handle the same process repeated for every user.

Reliable Archive Approach
For larger mailbox archives, it’s more convenient to use an advanced Office 365 backup solution instead of relying only on the Outlook exports. A solution such as GainTools Office 365 Backup Tool helps to create PST archives right from Office 365 mailboxes. It helps create Outlook-compatible backup files instead of having to export each account manually. It keeps the mailbox organized, so long-term storage and future access are much easier.

If you are archiving business mailboxes, then before you start the export, it is also worth deciding whether you need a backup of the whole mailbox or only specific folders. This can help you save storage space and make it easier to retrieve email later.

topic Re: Need help exporting Office 365 to PST for archive purposes in Alfresco Forum

Need help exporting Office 365 to PST for archive purposes

Re: Need help exporting Office 365 to PST for archive purposes