The Design of Everyday Things - A timeless book, The Design of Everyday Things explores the fundamentalprinciples behind all design, and how to understand the psychology behind how we use things, and why they frustrate us.
Mailook - Identify & fix your email deliverability issues for free 👀
The Elements of Typographic Style - The primary form of communication on the web is through text which makes typography one of the most important aspects to design for.
Mailivery - Reach the Inbox, not the spam folder.
CS50x - HarvardX (edX) - An introduction to the intellectual enterprises of computer science and the art of programming.
Postal - Open source mail delivery platform, alternative to Mailgun or Sendgrid