Windows 10: Can I add old mail from .pst to .ost without .ost file corruptions?

Whilst currently using Office 365 / Outlook on Exchange basis, I have been using POP3 for a very long time.
I still have connected my POP3 account (.pst) to Outlook.
Am using Outlook 365 as default.

I also have a gmail account, same situation as above applies: Gmail changed from POP3 to IMAP a couple of months ago.

I wonder what would happen if I were to massively copy old (pst) email to IMAP, so I would then close the POP3 files.

This may go fine for some mail, but in case of large numbers, would that then lead to file corruptions?
Assume that Exchange/IMAP sync normally is just one way, i.e. server > client, whereas client > server may only involve the status of mail (like: read, deleted).

Thanks.

:)

 

Copy Outlook .ost file to an offline device

If you are the owner of the Exchange profile, you can configure your account in the Outlook in the new computer and simply download the mailbox data from the Exchange server. But if you want to transfer OST file data
to another user, you can convert OST to PST and then transfer it to the new computer. The new user can import the PST file to his mailbox.

Let’s start the process:

Step 1- Locate OST in your system

To locate an OST file in your system, follow the below-mentioned steps:

·
Open Control Panel and click on Mail.

·
Select Email Accounts in the “Mail Setup” dialogue box.

·
Now, go to the Data Files tab and select the desired account.

·
Click on Open File Location to know the location of the OST file.

·
The location of your PST file will be opened

Step 2- Convert OST to PST

In this step, you need to convert OST to PST. Though you can export OST mailbox data to PST using
the Export feature of Outlook and you can use any third party OST to PST Converter.

 

Than can I convert OST files to PST.

How do I convert OST to PST and why a regular email with a regular account was suddenly stored in OST format if as it is said You have this Exchange account extension. Good day! Does anyone have a Converter from ost file to pst ?

 

.pst vs .ost

how do I change from .ost to .pst in Office 365?