Archiving or exporting your email in Microsoft 365


Use the following instructions to create an archive of your Microsoft 365 email. Save the archive file as a .pst file on a Windows device or an .ost for macOS devices.

Some individuals may have emails containing Personal Health Information (PHI). 

Per University HIPAA policy guidance on the use of email containing PHI, individuals must never send or receive an email containing PHI from any device except a Yale-managed computer or a Yale-managed smartphone. Per University compliance requirements, Yale faculty and staff must not create, store, access, transmit, or receive ePHI on personally owned computers. 

Only information for one account can be exported at a time. To export items from multiple accounts, repeat these steps for each account.

Outlook for Windows Operating System

  1. Select the File tab.
  2. Select Options.
  3. Select Advanced.
  4. Under Export, select Export.
  5. Select Export to a File.
  6. Select Next.
  7. Select Outlook Data File (.pst).
  8. Select Next.
  9. Select the account — a top-level folder — that you want to export. Top-level folders are identified by either the full email address or the designation: Mailbox - Last name, First name. This step enables exporting all mail messages, calendar items, contacts, tasks, and notes (if available) for that account. Verify that the Include subfolders check box is selected.
  10. Select Next.
  11. Select Browse to select where you want to save the Outlook Data File (.pst) and enter a file name.
  12. Select OK to continue.
  13. If you are exporting to an existing Outlook Data File (.pst), in the Options section, specify what to do when exporting items that already exist in the file.
  14. Select Finish.

Outlook for Mac Operating System (New Outlook)

  1. On the File menu, select Export. (Note: If Export is greyed out, use the Classic version of Outlook.)
  2. To export all items in Outlook, Select Items of These Types and select all the check boxes.
  3. Select Continue and then follow the instructions on the screen. (Note: The Outlook for Mac Data File uses the .olm extension.)

Toggle from New Outlook to Classic Outlook

  1. Select Outlook in the File menu.
  2. Select New Outlook.
  3. Select Revert.

Outlook for Mac Operating System (Classic)

  1. Select Tools.
  2. Select Export.
  3. To export all items in Outlook, click Items of These Types and select all the check boxes.
  4. Select Continue and then follow the instructions on the screen. (Note: The Outlook for Mac Data File uses the .olm extension.)