How to Add Transactional Email with Resend
Send notification and confirmation emails from your project — including domain verification and the deliverability basics.
Published 24 Aug 2026 · Tested with Lovable as of 24 Aug 2026
Overview
Transactional email covers form notifications, confirmations, password flows and alerts. It needs an email provider and a verified sending domain.
Beginner explanation: You cannot send email from a domain you have not proved you own. That verification step is why your first emails often fail.
Technical explanation: Store the API key as a server-side secret, send from server code only, and verify your domain with the DNS records the provider gives you.
Steps
- Create an account with the email provider and add your sending domain.
- Add the DNS records they provide and wait for verification.
- Store the API key as a server secret — never in frontend code.
- Send a notification email from server code when a form is submitted.
- Send a separate confirmation email to the person who submitted.
:::tip Send both emails: one to you, one to the submitter. The confirmation dramatically reduces "did it send?" enquiries. :::
What to check afterwards
- Notification arrives reliably
- Confirmation arrives and is not in spam
- Failures are logged rather than silently swallowed
Common problems
- Unverified domain. Emails silently fail or land in spam.
- API key in frontend code. Anyone can read it and send as you.
- No error handling. Form says success, nothing sends.
Where people get stuck
If you have followed the steps and the result still is not right, the fastest path is usually to describe the exact behaviour you expected, the behaviour you got, and any error text, then ask for a fix in one focused follow-up prompt. If that loop is not converging, hand it over.
