As SMTP support is getting tougher and tougher ([14945] Email still using TLSV1) I have been migrating some of my other systems over to a mail sending service that can more easily evolve over time. It seems to be easier to support and requires my apps don’t need to deal with SMTP.
The most recent one I like is MailGun. https://www.mailgun.com/ Its basically email for devs and backends where all interaction can be done via REST and webhooks. It might be something to look into an option for notifications and such in Ignition to support some type of REST style email service in the future.