Add/Remove Group Membership - Exchange Distribution Groups

Hello.

I'm unsure on the first question.
You'd need to edit user(s), and add them to groups, instead of selecting the groups and adding user(s).

For the second, check the permissions on the account used for Exchange scans:
https://documentation.solarwinds.com/en/success_center/arm/content/prepare-exchange-scans.htm#Setuprequiredpermissions
in particular, membership in the Exchange security group "Organization Management"

Thank you for your quick replies. I've confirmed the ARM Svc Acct is in the Org Management group.  

As far as the first question (maybe b/c I haven't been successful in getting this to work), but I have a user that has moved to a different department. While I'm removing them from 6-10 different AD groups (for drive mapping, folder access etc), I'd also like to remove them from multiple Exchange Dist Lists at the same time and add them to a few different ones. Does that make sense?

I'm unsure on this process, it's not something I've worked with yet.
You may want to open a support case and we can work on it with you.

Have you looked at utilizing Department Profiles, https://documentation.solarwinds.com/en/success_center/arm/content/create-a-new-department-profile.htm? Department profiles can contain AD attributes and group memberships that a user in said department should have. If a user changes departments you can apply the Department Profile that aligns with their new role and have the system correct AD attributes, add to missing groups and remove from extraneous groups automatically. 

Have you looked at utilizing Department Profiles, https://documentation.solarwinds.com/en/success_center/arm/content/create-a-new-department-profile.htm? Department profiles can contain AD attributes and group memberships that a user in said department should have. If a user changes departments you can apply the Department Profile that aligns with their new role and have the system correct AD attributes, add to missing groups and remove from extraneous groups automatically.