Mail Identity Cloud
Mail Identity Cloud helps a small group of invited mailbox users recognise senders in Apple Mail. The service looks up public sender logos and saves matching cards to a dedicated iCloud Contacts list. Apple Mail decides when to display a contact photo.
Why it asks for Google access
Gmail metadata helps identify senders from message headers. Read-only Google Contacts access helps avoid duplicate cards. Each mailbox user grants access separately.
For help, contact the administrator who invited you.