Hi Mark,

You can achieve it simply by adding a condition in your inbound email action like

email.from.indexOf("group_name") !-1

But it will run only in case of mails sent on behalf of group.

Alternatively, you can use a glide record query to check if the user is a member of a particular group/groups.

Here's a thread discussing same : how to see if updated by is member of a group

Thanks,

Mandar

EDIT : You can also use the isMemberOf( ­'group_name') functionality provided by service now.