To perform Export office 365 mailbox to PST from admin portal task can be effortlessly done by Shoviv Exchange Recovery manager tool.

Furthermore, users can export Office 365 directly into the Live Exchange Server with ease. This software also makes the recovery of corrupted and inaccessible Office 365 mailboxes. After the recovery, it restores the recovered file to the desired location.

Try its free evaluation version to check its functionality.

To know more:

Exchange 2010 migration to office 365  

Exchange Mailbox Backup

Upgrade Exchange 2016 to Exchange 2019