There are myriad different types of groups in Office 365.  Before selecting the group type that you want to use, it is important to understand the pros and cons of each group-type. This article outlines my thoughts regarding when to use a distribution group (not Office 365 distribution groups) vs. an Office 365 group. I expound on my reasons for using disparate groups in the table below. Personally, I think corporate groups (HR, all employees, etc.) are much better suited for distribution or dynamic groups. With that said, I do understand arguments asserting corporate groups should be O365 groups.


Group Type Large Audience Changing Groups User Created Administrator Created
Distribution Group X X
Dynamic Distribution Group X X X
0365 Group X X X


  • Large Audiences – For groups with large audiences, it depends on the type of groups. I like the idea of keeping a running history of content for large groups. For example, an IT-All group could contain previous conversations that are easily searchable in one location. The downside to O365 groups is that messages may not be delivered to inboxes (depending on how/when the group is configured). Unless end-users are in the habit of checking O365 groups daily, important messages could be missed.
  • Changing Groups – Dynamic distribution groups are great for large groups that are dynamic in nature. The delivery time, calculated from when the sender clicks send to when the recipient receives the email message, may be higher with dynamic distribution groups. Dynamic distributions perform an Active Directory lookup every time a message is sent to the group, ensuring the most up-to-date group membership is used. Users will be able to create dedicated groups if enabled (
  • User Created – Users can create and manage O365 groups. Administrators, depending on where the group is (on-prem vs. cloud), have to manage distribution groups. Dynamic distribution groups are managed by administrators only.
  • Administrator Created – Administrators can create all group types.


Group Type Collaboration Resources Friendly SMTP Address ( Manage within Outlook Previous Conversation History
Distribution Group X
Dynamic Distribution Group X
0365 Group X X X X



  • Collaboration Resources – O365 groups provide additional functionality over the standard Exchange groups. O365 groups also share calendar, OneNote notebooks, Skype messages, and SharePoint data.
  • Friendly SMTP Address – When creating an O365 group, the SMTP address of the O365 group is the default O365 domain. Using Exchange Address Book Policies (EAPs), the SMTP address is based on the group membership.
  • Manage in Outlook – Groups created in the cloud, specifically O365 groups, can be managed through Outlook and OWA.
  • Conversation History – O365 groups keep track of email conversations. The one question I have out to Microsoft pertains to O365 groups and retention policies. I believe it should adhere to the mailbox policy. I’m currently testing my theory.


Group Type Suggestive groups Internal/Federated Only Objects Message Approval Hide From Gal
Distribution Group X X
Dynamic Distribution Group X X
0365 Group X X


  • Suggestive Groups – Within OWA, the suggestive group’s picker will display O365 groups that the user might want to join.
  • Internal/Federated Object – From an email perspective, contacts cannot be members of O365 groups unless they are federated or trusted.
  • Message Approval – The moderation of approving an email message is not available in O365 groups (at least I couldn’t find a way to enable this service).
  • Hide from GAL – The Hide from GAL is available in the GUI for Dynamic and Distribution groups. For O365 groups, this setting is enabled via PowerShell.


Group Type Suggestive groups Internal/Federated Only Objects Message Approval Hide From Gal
Distribution Group X X
Dynamic Distribution Group X X
0365 Group X X X