Sends email using the Gmail API with OAuth2 authentication

There are a few preconditions that must be met before this adapter can be used to send email:

1. Admin access to a GSuite account
2. Implement server-side authorization
3. Grant the service account domain-wide authority
4. Authorize API client with required scopes

Some application settings must be configured. See the example section below.

Config Settings

Required GmailAdapter settings:

adapter: Bamboo adapter

sub: Email address the service account is impersonating (address the email is sent from).

- If impersonation is not needed, then `nil` (it is likely needed).

Required Dependency settings:

json: Google auth crendentials must be povided in JSON format.

- These are generated in the [Google Developers Console](https://console.developers.google.com/)

Optional settings:

sandbox: development mode that does not send email.

- details of the API call are instead output to the elixir console.

Note:

Secrets such as the service account sub, and the auth credentials should not be commited to version control.

Instead, pass in via environment variables using a tuple: {:system, "SUB_ADDRESS"}, or read in from a file: "creds.json" |> File.read!

Example Config

config :app_name, GmailAdapterTestWeb.Mailer,

adapter: Bamboo.GmailAdapter,
sub: {:system, "SUB_ADDRESS"},
sandbox: false

# Google auth credentials must be provided to the goth app config :goth, json: {:system, "GCP_CREDENTIALS"}

Google Authorization/Authentication Help

The Google-related preconditions described above may be a little tricky. If you find yourself stuck, please refer to the wiki for help.