The group named "Unclassified Group" is a system created and system managed group. It cannot be edited or deleted. 

Any contact added to your database that is no yet associated to a specific group will be automatically added to this unclassified group.

If you have contacts listed in that group, that means they are not currently a part of any groups in your PastorsLine account. 

Once you add them to a group, they will be removed from the unclassified group automatically.

This is just one more way to help you manage your subscribers. Double check this group and see if any action is needed. Maybe they have not finished a data capture or need to be deleted from the database.