Write-protect Outlook PST file

Question

I am looking for a way to write-protect Outlook PST files, so that one cannot accidentally delete mails from or add mails to the PST file. The file is an archive and shall be accessible read-only from Outlook.

Simply write-protecting the file on file-system level does not work since Outlook refuses opening the file.

Answer 1

I think you might be out of luck. Microsoft actually has an official stance on this.

Answer 2

You would need a third party solution like nearpoint. I would instead suggest you to not use PST files and keep the mail on the exchange server. This will allow you to use mailbox permissions to protect the email in question.