Exporting your entire Office 365 mailbox to a PST file is a useful way of creating an offline copy of your emails, attachments and all the other mailbox data. It's a way of having a local backup which can be used for long term archiving, data protection and mailbox migration.

You can use Outlook's built-in export function or go for a dedicated backup solution if you want more flexible backup and restore options.

Manual Method to Export Office 365 Mailbox to PST

1. Open Microsoft Outlook and sign in to your Office 365 account.
2. Navigate to File > Open & Export > Import/Export.
3. Select Export to a file and click Next.
4. Choose Outlook Data File (.pst).
5. Select your mailbox and enable Include subfolders.
6. Choose a destination folder and click Finish.
7. Verify the exported PST file to make sure the required mailbox data is in there.

This is the approach you'd take for accessible mailboxes. If you're looking at managing multiple accounts or backing up some additional Microsoft 365 workloads then you're likely to need a more complete solution.

Use BreviSoft Office 365 Backup & Restore Tool

The BreviSoft Office 365 Backup & Restore Tool is a dedicated tool for backing up Microsoft 365 data and keeping an offline copy on your local system. It lets you manage your backups and prepare to restore your data when needed.

Key Features of BreviSoft Office 365 Backup & Restore Tool

1. Offline Microsoft 365 Backup: Back up supported Office 365 data to your local machine for future access and archiving.
2. Emails, Contacts, Calendars and Documents: Back up the supported Microsoft 365 data types as per the available export options.
3. Shared Mailbox Backup: Backup the data from a shared mailbox to a local location where supported.
4. In-Place Archive Mailbox Backup: Back up supported Office 365 in-place archive mailbox data.
5. Date filter: Select emails within a specific date range for more targeted backups.
6. Bulk Mailbox Backup: Allows administrators to back up multiple Office 365 mailboxes using authorized admin access.
7. Single User Backup and Restore: Support backup and restore for individual accounts where the tool's auth and permissions permit it.
8. Delta backup: Back up only the newly added or changed data (rather than doing a full backup) if this is supported by the selected backup workflow.
9. Restore Support: Assist in the recovery of backed-up data using the restore options available.

Conclusion

If you just need to export one accessible mailbox, then the built-in export wizard in Outlook is a perfectly fine option. If you're looking at something more comprehensive for your backup needs then the BreviSoft for Office 365 Backup Tool is definitely worth a look at for offline Microsoft 365 backup and protection, selective backup and recovery planning.

Before you start, check the tool's supported workloads, authentication requirements, export formats and restore capabilities to make sure they meet your organization's requirements.