A couple months ago I created a security group that can also receive internal email and added most of our staff members to the list. Everything has worked fine up to now. Today I tried to add a new staff member to the group and got the following error.
"Archived email site does not exist"
It would not let me add the new member after the error. I found that I could delete the group and recreate it with all the names I needed, but if I tried to edit the membership after creation, it failed with the same error.
No mention of this error on google, and there doesn't seem to be anything in the event logs.