Export in new Outlook
Outlook Data File (.pst) support in new Outlook provides access to emails stored in a .pst file. You can browse, manage, and move emails (drag and drop) between .pst files and mailboxes. See Open and close Outlook Data Files (.pst).
Important: Calendar and contacts items saved in .pst files is not available in new Outlook at this time.
To export an Outlook Data File (.pst), go to Settings Glyph Library: fluent Glyph Name: Settings > Files > Export.
Select Get started.
Follow the steps in the wizard to select the mailbox or specific folders you want to export.
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hth
Marcin