I'm an admin of a group, the permissions got set to the default team setting for the email group google voice was forwarding to. I have since resolved this to allow anyone on the internet email this group but it then started sending emails from google voice to spam. I was able to search spam and mark them as 'Not Spam' but this only worked for half of the people. I am still having problems with a few accounts sending the google voice email to their spam and do NOT think that creating a filter for each account is an acceptable fix for this issue. Also, I have checked their contacts and google voice's email address is listed in there. Anyone have any ideas?
You can set up a new filter for these messages if there is some sort of unique identifier in them to match against the filter. I don't know what you would use off hand, but it could be something in the from, to, or subject fields. In the actions for the filter, check Never Send to Spam.