Use HTML content, as well as plain text alternative.
Use it hassle free from Azure or from your Windows box
EmailEngine also sends webhooks whenever something changes on the registered accounts. You can either use Bitcoin or PayPal for donations. If you really like Nodemailer or your business benefits from it financially then I would really appreciate a small donation. If you are upgrading from Nodemailer v2 or older, then see the light migration guide here.
Nodemailer is licensed under MIT license. The project got started back in 2010 when there was no sane option to send email messages, today it is the solution most Node.js users turn to by default. Nodemailer is a module for Node.js applications to allow easy as cake email sending.