TL;DR: Password reset emails were landing in Gmail's spam folder. Not occasionally — consistently. 📖 Reading time: ~31 min What's in this article I Needed Reliable Transactional Email — So I Tried All Three The Setup Reality Check (Before You Pick Anything) AWS SES: Cheapest by Far, But You're On Your Own Postmark: The One That Just Worked Resend: New Kid, Built for Developers Side-by-Side: The Numbers and Dealbreakers Real Code: Sending the Same Email on All Three When to Pick What — Match the Tool to Your Situation I Needed Reliable Transactional Email — So I Tried All Three Password reset emails were landing in Gmail's spam folder. Not occasionally — consistently. My small SaaS app had maybe 200 active users at the time, and I was getting support tickets every week from people who never got their confirmation emails. The culprit was SendGrid's free tier, which shares IP pools across thousands of accounts. When one of those accounts sends spam, your deliverability tanks too.…