Office 365 being the convenient work-horse that it is, there are multiple items that can be confusing and something that will take some getting used to. Today we are going to talk about one of these scenarios, and that is when to use Distribution Groups and when to use Security Groups.
First off, I will start off explaining why it is so confusing. When you first log into the Microsoft Online Portal, you are directed to the “Admin Overview Page”. From here you can select “Users and Groups”. Simple right? You would think that you could manage everything “groups” related from this one spot. Wrong! From this location, you can create and manage “Security Groups” and “Mail-Enabled Security Groups”.
To add more confusion to the mix, a “Mail-Enabled Security Group” looks and functions similar to a distribution group. One of the differences, and MOST important difference, between the 2 are a “Mail-Enabled Security Groups” require an owner that manages every aspect of the group including membership. Once an owner is assigned, not even a Global Administrator can modify/delete the group. A “Distribution Group” does not require this.
To clarify where these 2 differ and when to use them, remember this one VERY simple rule of thumb. If you are strictly “cloud based” (meaning you are using ONLY Office 365), then you should only utilize “Distribution Group” function. If your solution is federated with on on-premise exchange server (meaning you are using Office 365 AND an on-premise Exchange Server) then you would ONLY utilize “Security Groups” to manage permissions and NOT to send mail to.
Anytime you need to create a group that you are going to be sending mail to, then ALWAYS use a “Distribution Group”. If you are needing a group that will manage permissions of users and items when you have a federated environment, then utilize a security group.
As confusing as this all may be, if you remember the rule of thumb listed above, then you should be in a great spot. If you have any questions, Everon has a group of engineers that are specialized in Office 365 and would be more than happy to answer your questions.