It seems like it should be possible to transfer a membership rule from an Exchange dynamic distribution list to a dynamic Microsoft 365 group/team, but it’s not. Different directories, schemas, properties. and syntax conspire to stop easy conversion. It’s a pity, but that’s the way life and technology sometimes go…
This article explains how to create a new Microsoft 365 group and team using the membership and properties of an Exchange Online dynamic distribution list. The process is reasonably straightforward, but as always with PowerShell, there are some interesting turns and twists that must be navigated en route.
Microsoft is changing the way the Exchange Online transport service resolves the membership of dynamic distribution groups. Instead of doing this when someone sends a message to a dynamic group, Exchange resolves the membership once daily and whenever the recipient filter changes. It’s a reasonable approach designed to make messages move faster and more reliably, and it’s similar to the way that Azure AD dynamic groups maintain their memberships, so it shouldn’t make much difference.