Emulate sendmail via Gmail API
This can be used as a sendmail-compatible binary that will send emails via the GMail API, possibly with queue.
Use the gmail-sendmail binary as "sendmail". If a ~/.gmail-queue folder exists, it will queue up any sent emails there, if not it will immediately send them.
If you have queued any emails, you can run gmail-sendqueued to process the queue and send the emails out.