GMail API - Can I send email using the Service Account?

Question

When I send an email using the GMail API, I get an Access Token for the user to whom the message is to be sent and then when sending the message, I put some value in the From Field.

But no matter what I put in the from field, the message in the email shows as From "Me" and is in the Sent mails as well as Inbox.

Is there a way, I could use the Service Account to send the email, so that it does not show up as From "Me" and is also not in the Sent Mails.

Answer 1

No. The Gmail API is for Gmail users and service accounts are just for doing auth to a real Gmail account, they don't have their own Gmail account, etc.

If you want to send the email from some service, you need some bulk-sending email service like at: https://cloud.google.com/compute/docs/tutorials/sending-mail/ or something you run yourself or from some other provider.

Answer 2

You cannot use a service account to impersonate a free gmail account. I spent a lot of time confirming this after reading a reply that was here before. Maybe it worked at some point, but it doesn't anymore.

There is no way to share / grant another user permission to access your standard gmail account. So there is no way for you go delegate the permissions for [email protected] to access [email protected].

and

you can impersonate G-Suite accounts but not Gmail accounts

These quotes are from Google's official C# Auth repo:
https://github.com/googleapis/google-api-dotnet-client/issues/1561