Many companies do not use Google services — because of privacy concerns, because local legislation does not allow them to share their operational information with US-based companies, or simply because they just don't like their products. Unfortunately, right now the only way that Taskade has to allow the user to send an email is via a Gmail account (or via an HTTP request, if they subscribe to a commercial service and are tech-savvy enough to know how to structure the request for the service's particular API...).

Most users who are not on Gmail will have an email account that supports SMTP — the standard for email sending. It would be incredibly helpful if Taskade supported sending transactional email messages via SMTP, rather than forcing users to use Gmail...