File > Account Settings > E-Mail > Change Folder. Set each account to use your 'old' PST file.
File > Account Settings > Data Files - set your 'old' file as the default.


You should then be able to close any other, now unwanted, PST file from the 'Folders' pane.

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Graham Mayor - MS MVP (Word) (2002-2019)
Visit my web site for more programming tips and ready made processes www.gmayor.com

Thanks very much for reply.
But not much luck:
- File > Account Settings > E-Mail > Change ... but not sure what happens now.
Here I have my user name and email address and password etc.
Am I to change my email address to my old pst name (ie outlook.pst)?
I thought email addresses were supposed to have a @

- File > Account Settings > Data Files
I changed "Outlook Data File" from being default, to "Personal Folders" being default (it would not allow me to set my email address as Default).
It didn't fix emails not going to Inbox under "Personal Folders"... and my Address Book is still empty.