Resend

Transactional email built for developers — send a welcome mail or receipt with one API call, and actually land in the inbox.

What it is

An email API with a clean SDK and good deliverability defaults. You POST a from/to/subject and HTML (or a React email), Resend sends it, and handles the domain auth (SPF/DKIM) that keeps you out of spam.

When to use it

For transactional email — the messages your app sends one person in response to an action: confirmations, magic links, receipts, password resets. It’s the fastest way to add “and then email them” to any workflow.

When NOT to

It’s not a marketing/newsletter platform with campaigns, segments, and drip automation — reach for a dedicated ESP there. And you still need a domain you can verify; you can’t send trustworthy mail from an address you don’t control.

Used in

Sends the confirmation email in Build a Waitlist Page, and is the email piece of the AI SaaS Stack.