Nodemailer vs Postal: What are the differences?
What is Nodemailer? A module for Node.js applications to allow email sending. It is a single module with zero dependencies – code is easily auditable. The email delivery is Secure using TLS/STARTTLS. You can use HTML content, as well as plain text alternative.
What is Postal? Open source mail delivery platform, alternative to Mailgun or Sendgrid. Postal is a complete and fully featured mail server for use by websites & web servers. Think Sendgrid, Mailgun or Postmark but open source and ready for you to run on your own servers. Postal was developed by aTech Media to serve its own mail processing requirements and we have since decided that it should be released as an open source project for the community.
Nodemailer and Postal can be categorized as "Transactional Email" tools.
Postal is an open source tool with 9.14K GitHub stars and 538 GitHub forks. Here's a link to Postal's open source repository on GitHub.