Data guides
Outlook / Exchange: see how much data you have, then export it.
Pick a system to see two things: how to check how much data is in it, and how to export a copy. No form, no sign-in.
Outlook / Exchange
Email & communication
How to see how much data is in Outlook / Exchange
- Sign in to the Microsoft 365 admin center with an admin or Reports Reader role
- In the navigation menu, select Reports (if you don't see it, select Show all → Reports) → Usage
- On the Usage page, under Reports, select Exchange, then on the Email activity tab select View More
- From the Email activity drop-down list, select Exchange → Mailbox usage
- Read the Storage chart, switch the drop-down at the top right of the charts to Shared for shared mailboxes, or select Export to total Storage used (MB) per mailbox
Record user plus shared mailbox storage used; the Storage chart does not include archive mailboxes, so add those separately if you use them.
Outlook / Exchange’s official instructions
How to get a copy of your Outlook / Exchange data
- In classic Outlook for Windows, click File → Open & Export → Import/Export
- Choose Export to a file, then Next
- Choose Outlook Data File (.pst), then Next
- Select the mailbox, check Include subfolders, then Next
- Click Browse to pick where to save the .pst file, then Finish
Export mailboxes through Microsoft Purview Content search or eDiscovery, or as PST files from Outlook.
Shared mailboxes and archive mailboxes are often forgotten. Include them if they hold company history.
These instructions are written by DataFrenzy from each vendor’s public help pages. Menu names can vary by plan and change over time; the official link on each guide is the final word. Screenshots come from each vendor’s own help pages and videos or, where noted, from third-party tutorials credited under the image; dashed outlines are illustrations, not screenshots. Looking up a size or preparing an export never sends anything to DataFrenzy.