I have the Access Request feature enabled in my O365 SharePoint site. This functionality is working fine for a single site collection admin user's Email-ID and he is receiving the mail in his Outlook with an option to Approve/Deny the request. But when I specify the Email-ID of a Distribution Group (which consists of all the site collection admins), the mail is not sent to their respective inboxes although the corresponding request is listed under the Pending Requests in the Access Requests list in Site Settings. Why is this happening?
Also I would want to know what is the minimum permission level required to Approve/Deny these Access requests? Does the user needs to be a Site Collection Admin?