Export Mailbox to PST
In your Exchange admin center go to permissions and double click Discovery Management.
This and the next step are necessary, because you need to be a member of the Discovery Management role group to be able to use eDiscovery features.
In the Discovery Management role group properties window add your account to the Members list using the plus button and click Save.
Make sure that Legal Hold, Mailbox Import Export and Mailbox Search roles are added in the Roles section (if not, correct this using the plus button).
Back in Exchange admin center, go to compliance management, click the plus button to start a new in-place eDiscovery & hold wizard, type in a name and click Next.
If you want to export data from all mailboxes, select Search all mailboxes.
Or select specific mailboxes using the Specify mailboxes to search option, and then clicking the plus button. This will open a new window – highlight the mailboxes you want to export data from, click add → and OK.
Additionally, you can enable exporting from Public folders by checking the Search all public folders option (in the Public folders section at the bottom of the window)
The next step gives you several filtering options (unless you want to export all data, in which case select Include all content):
- keywords/phrases (separated by logical operators: AND, OR, NEAR, NOT, etc.)
- time ranges
- From/To/CC/BCC fields
- and message types (which can be defined in the window that opens when you click the select message types… button).
After clicking Finish a dialog box will show the progress of settings being saved. When it finishes click Close.
Now that you have set up an eDiscovery search, you can export its results to PST files. To do this, click the downward arrow button (marked red in image below).
A ClickOnce application called eDiscovery PST export tool will start. Point it to a folder where you want to save the PST files.
Do not check the Enable deduplication option, unless you want the search results to be exported to a single PST file.