To make sure your Active Directory distribution groups sync up to Office 365, fulfill the following requirements:
- The group (whether Security or Distribution) is Universal
- The group's email field is populated with an email address
- You don't have to do this for security groups that will never be used to secure access to Exchange Online objects. However, i suggest that you fill out the email address anyway to avoid confusion later and for the sake of consistency.
- Use the group's alias when creating the email address. This will ensure that you're not accidentally stepping on an existing email address. For example, if your group alias is dg-nyc-execs, the email address would be firstname.lastname@example.org.
- The group's displayName property is filled out
NOTE: in order to get to the displayName property, you should enable Advanced Features in Active Directory Users and Computers (see screenshot below). Once you do, for every object you open, you will see an Attribute Editor tab and will be able to access all object attributes. Alternatively, you may need to use ADSIEdit to get to the attribute.
Once you set all the properties on your group, as discussed above, either force directory synchronization or wait for it to take place as scheduled.
If you have questions or would like MS Online Helpdesk to help you with this task, please create a new support ticket.