Email with Resend

Resend is the connector for transactional email: the messages your app sends because something happened. A booking confirmation, a receipt, a "your report is ready". This guide covers connecting it, asking for email features, and the separate Pro option of sending your app's sign-in emails from your own domain.

Connect it

1. Create a Resend account and key

   In the Resend dashboard, create an API key. To send from your own domain (orders@yourshop.com instead of Resend's test address), also add and verify your domain in Resend; it walks you through the DNS records.

2. Paste the key into Vaulter

   Open Vault → Connectors, pick Resend, and paste the key into the secure form. It lands in Vaulter's connection layer, never in your code.

3. Ask for the email

   Describe the trigger and the message:

   When someone completes a booking, email them a confirmation with the date, time, and a cancel link. Send it with Resend.

What to know about app email

• This is an owner-shared connection: every email your app sends goes through your Resend account, and Resend bills you by volume. The owner spend quota can cap it.
• The sending address matters. Until your domain is verified in Resend, mail goes out from a Resend-provided address and lands in spam more often. Verify your domain there before launch, then tell the agent the from-address to use.
• Write the emails like product copy. Tell the agent the tone and the essentials for each message; you can paste the exact wording you want and it will be used verbatim.

The other email: your sign-in emails, from your domain

Separate from the connector, apps with sign-in send their users one-time codes and sign-in links. By default those come from Vaulter's own address. On Pro, you can send them from your domain instead: open Vault → Auth, find the Emails card, and enter your domain. Vaulter shows the DNS records to add; once they verify, your app's auth emails carry your sending identity and your logo.

Two details:

• Verification status shows as pending, verified, or failed on the card, and can take a little while after you add the records, like any DNS change.
• This feature needs no Resend account and no connector; it is part of the platform. Removing the domain from the card returns auth emails to the vaulter.run sender, which is also the escape hatch if the workspace later leaves Pro.

Frequently asked

Can my app send marketing blasts with the Resend connector?

The connector is aimed at transactional mail, and your app can also read your Resend audiences, domains, and broadcasts to display them. Run large campaigns from Resend's own dashboard, where the deliverability tooling lives.

Emails send in preview. Is that real?

Yes. A connected Resend key sends real email from the preview too, so test against your own address until the flow is right.

An email failed to send

Check the Resend dashboard first; it logs every attempt with the reason. The usual suspects are an unverified sending domain and a recipient address typo. If Resend shows no attempt at all, the call was stopped on the Vaulter side; the limits page covers the three ways that happens.