I inherited an O365 cloud only mail environment. There are many "outside" contacts that need to be included in the dynamic distribution groups that are triggered by the custom attribute fields.
I see that previous mail contacts were flagged with custom attributes, but I can't seem to figure out how to do this myself. The option is not available in the GUI, and I've scoured the forums for a powershell command that might do this but have not been successful yet.
Can anyone shed some light on this for me?