One of the challenges you can encounter when moving to Office 365 is dealing with large messages in mailboxes. Most migration tools either skip the messages that are too large for Office 365 or just fail the migration. Using PFDAVAdmin or Exfolders can identify the messages, but then deleting the messages is still very much a manual process….until now.
MessageOps Large Message Exporter allows you to quickly identify large messages in your on premise Exchange environment. Once found, the utility can backup those messages to a PST file, and delete them from the on premise mailbox allowing you to migrate the mailbox to Office 365.
MessageOps Large Message Exporter is free for everyone to download and use.