I have not been able to find any good explanations of which of the following options to choose when exporting a full email account to a .pst backup (that would eventually be loaded as a data file on a different instance of Outlook).

Every result showing this, advises the first option, however I don't want to err on the side of data-loss and I'm doing a one time backup before changing mail servers. Which of the 3 options below are best for that?

Does 'replace duplicates with items exported' affect your actual e-mail account or just the exported .pst?

*The version of Outlook being used here is 2016.

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All of these options ONLY impact the .pst file you are creating.

I don't know how closely Outlook compares to determine a duplicate, but as I read these three options, the second one would have the least data loss as it will allow duplicate emails to be retained as unique messages, and it will also result in the largest possible .pst size.


PST files are just local files, which are not synced back to the mail server. So your source data won't be affected.

Just personal understanding as I haven't found any official documentation, the three options matter only when you choose an existing PST file which already have data in it. If you name a new PST file, no need to bother with the options. Of course, to avoid unexpected data loss, it's recommended to select the second option.

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