Security policy is requiring us to update passwords regularly, and this includes service accounts previously in use for services such as SMTP from our web servers. We are looking to use the Gmail API (Google is the company email provider) to authorize sending emails from the Sitecore web servers for basic email communications with CMS users and admins (password resets, etc.). We understand the Gmail side of things well enough and can create an app and credentials, as outlined here: https://developers.google.com/gmail/api/auth/web-server
However, I do not see any way to do this natively in Sitecore without a custom extension of some kind. Google provides a doc on a custom .NET app to send email, but this is not Sitecore specific. https://developers.google.com/gmail/api/quickstart/dotnet
How could this be done in a manageable way or is there a reliable code resource? I have searched, but find zero.