Hi, @Anubhuti
The answer to Zafer KAYA is very detailed.
If you prefer a graphical interface, you can also use the following method to export from a mailbox to the PST. If you have a large number of mailboxes, this may require performing this operation multiple times.
Note that this operation requires priority assignment of the Mailbox Import Export role.
More information can be found at Procedures for mailbox exports to .pst files in Exchange Server | Microsoft Learn
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