Via G Suite, we could provide e-mail addresses for members and contributors without it costing us anything. I'm thinking we should use something on the form of firstname.lastname@example.org – "friv" for "frivillig" (volunteer). Since we're using G Suite, they'll work like normal Gmail accounts. The reason we should use this form and not just email@example.com is to make it clear to recipients of emails that the person they're getting emails from is a volunteer that doesn't necessarily represent Wikipedia.
It should be made very clear to the users that this comes with elevated rights for those that admin the e-mail account, inclusive their ability to wipe the volunteers devices.
G Suite Administrator Help : Manage user devices from an Android device (subpoint "Wipe a device’s data")
The technical aspects of this are all set up and ready to go, but there are some other considerations, especially privacy (keeping GDPR in mind) and policy (what should be the criteria for getting an e-mail like this) that need to be sorted out. This is something we need to think more about how to figure out, so putting it on the back-burner for now.