Email

Overkill for a weekend project, but worth it once you need real behavioral triggers across email, push, and SMS and your user base has outgrown simple broadcast sends.

Built for SaaS teams who want lifecycle, marketing, and transactional email in one tool instead of stitching together three. Visual workflow builder is genuinely usable without a marketing ops person.

Open source, cheap ($0.001/email), and a fair Resend/Mailchimp alternative if you want to self-host or just don't want per-contact pricing creeping up as your list grows.

Rock-solid for transactional-only mail (password resets, receipts). Keeps that traffic on separate streams from marketing mail so one bad campaign doesn't tank your login emails' deliverability.

Email API built by the React Email team, so if you're already writing templates as JSX this is the least friction way to send them.

The default choice once you need serious volume and don't mind a bigger, more enterprise-flavored dashboard (now Twilio SendGrid). Deliverability infrastructure is proven at massive scale.