Large PST Files Taking Up Space? Is Office 365 Migration Worth It?

Large Outlook PST files can become difficult to manage when employees keep adding years of emails, attachments, contacts, calendars, and other mailbox information. Apart from consuming local storage, maintaining multiple PST archives across different computers can make it harder to organize and access historical information.

I’m currently looking at whether moving older PST data into Microsoft 365 would make mailbox management easier. One advantage seems to be having the information available through a centralized cloud mailbox rather than depending entirely on locally stored archive files.

Before starting, though, I think it is important to decide exactly what should be migrated. Some users may need their complete archive, while others may only require emails from certain years. Transferring unnecessary attachments and outdated messages could increase the amount of data that needs to be processed.

The SysInfo PST to Office 365 Migration Tool caught my attention because it supports batch migration and can transfer PST data to Primary, Shared, and Archive mailboxes. The product also provides a date filter, attachment exclusion option, and duplicate-removal functionality, which could be useful when preparing older archives.

Duplicate emails are another issue I would check before migration. If the same messages exist in several PST files, importing all of them could create unnecessary clutter in the destination mailbox. Removing duplicates based on email properties can help keep the migrated data more organized.

The import PST to Office 365 tool should also be evaluated for its ability to preview source content before migration. Being able to review messages and attachments first can help prevent incorrect folders or unnecessary data from being transferred.

For larger projects, I would probably test a few representative PST files first and verify folder hierarchy, attachments, contacts, calendars, and mailbox access before migrating everything.

A properly planned PST to Office 365 migration can be useful when organizations want to reduce dependence on local PST archives, but the migration strategy should be based on data volume, mailbox requirements, and the amount of historical information that actually needs to be retained.

Has anyone here moved very large PST archives to Microsoft 365? Did it noticeably improve storage and email management afterward?