Access email from Gmail from server

Question

I am trying to be able to set up a cron job to read contents from a certain email in my gmail inbox daily. I lookeed up gmail api documentation and noticed that the only way to authenticate my requests to access email data is via OAuth 2.0 which requires user authorization. Is there a way to authorize my app to access emails from a particular email id without the need for the user to manually take any actions.

I found this: https://developers.google.com/identity/sign-in/web/server-side-flow. I was wondering if there is any way to follow this workflow without having to build the UI?

Answer 1

Technically speaking you can use Oauth2 you just have to have the user authentication your application once. You will get a refresh token then you can use the refresh token to get a new access token from cron. Unless this is a Google domain account you cant use service accounts. There is no way to pre authorize a service account to access a normal user gmail.

Alternative: have you considered going directly though the mail server? Skip the rest api. https://developers.google.com/gmail/oauth_overview Note: That page also speaks of XOauth2 I haven't tried it yet you can still access SMTP and IMAP using username and password.