How do I move Exchange files to Office 365 that exceed online size limits? #M365AMA

In this episode, the #M365AMA panel discusses the following community question:

“I have a client I recently took on who has Exchange 2010 which I’m going to migrate to Office 365. The issue is someone in the past has lifted the message size restriction and they have email’s over 150Mb! Office 365 doesn’t support messages this size so unable to import them. Has anyone come across this and what solution have you used, other than opening each mailbox searching for large emails manually exporting them, and then saving them somewhere. There are a lot of mailboxes including users who have left so not a slick process and being Exchange 2010.”

Check out the discussion here:


Participating in this discussion were:

Some relevant notes/links shared by the team:

Christian Buckley

Christian is a Microsoft Regional Director and M365 Apps & Services MVP, and an award-winning product marketer and technology evangelist, based in Silicon Slopes (Lehi), Utah. He is the Director of North American Partner Management for leading ISV Rencore (, leads content strategy for TekkiGurus, and is an advisor for both revealit.TV and WellnessWits. He hosts the monthly #CollabTalk TweetJam, the weekly #CollabTalk Podcast, and the Microsoft 365 Ask-Me-Anything (#M365AMA) series.