Exchange 2013
I was recently working with a client where they had Exchange 2007 and were migrating to Office 365. Our plan was to use an on-premises Exchange 2013 server to host Public Folders temporarily until a new solution was determined. As the project progressed and all the mailboxes were moved to the cloud, the client was having doubts about the placement of Public Folders on-premises due to many reasons (performance, backups, etc). Now we were tasked with moving their PF infrastructure to the cloud. If you dig around long enough in blog articles and Microsoft’s own guides, you get the feeling that there is no documentation or support for moving Exchange 2013 Public Folders to Office 365. In fact, this is indeed true. At this time, Microsoft does not support moving Public Folders from Exchange 2013 to Office 365. Yes, you read this correctly. There is NO native method. You must use a third-party tool like Bit Titan (which works, with caveats). From what I understand, this can take time to move folders just because of the background processes involved.
I for one find this extremely disappointing as this is a gaping hole in the product line and support for Exchange migrations.
TIP So if you are migrating from Exchange 2007 or 2010, make sure to follow the documentation for Public Folders to Office 365. Do not stop at Exchange 2013 along the way for any reason. Move straight to the cloud. Also remember that you do not cutover Public Folders to Office 365 until ALL mailboxes have been moved to Office 365. Similar to Exchange 2013, a ‘legacy’ mailbox (Exchange 2007/2010) cannot access Modern Public Folders which are present in Office 365 and Exchange 2013.
Further Reading
Configure legacy on-premises public folders for a hybrid deployment
Use batch migration to migrate legacy public folders to Office 365 and Exchange Online
