The best way to back up Office 365 shared mailboxes to local storage is with a dedicated tool like Shoviv Office 365 Backup Tool. Connect using admin credentials, select the shared mailboxes you want, and save them locally in PST, MBOX, EML, MSG, or HTML format. Filters by date or folder keep backups targeted, while scheduled and incremental backups save only new items and avoid duplicates. Multiple jobs can run together, which helps when you manage many mailboxes. It works without Outlook, and backed-up data can be restored into Office 365 mailboxes later. Try the free demo first to test it.
Read more : https://www.shoviv.com/office365-backup.html
Read more : https://www.shoviv.com/office365-backup.html