Overview

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No sender configured
Add a Resend API key to start sending Not set
Sending domain
Not set
API key
Missing
Sent this session
0
Last inbox score
Not run
Provider
Resend

Send pipeline

0 of 5 ready
Last message Nothing sent yet
Queued
Sending
Accepted
Delivered
Opened

Delivered and Opened stay dashed until you point a Resend webhook at this app. Accepted means Resend took the message — the last hop is the recipient's mail server.

Recent sends 0
Inbox check notes 0
Step 01

Sender identity

The name and address recipients see, plus the Resend key that authorises the send. Keys are stored server-side and never returned to this page.

Create one at resend.com/api-keys.
Use onboarding@resend.dev while testing, or any address on a domain you've verified in Resend.
Shown beside the address in most mail clients. Keep it recognisable — unfamiliar sender names are the fastest route to the spam folder.
Step 02

Connection

Calls the Resend API with your saved key to confirm it's valid and active. No SMTP port needed.

Saved configuration

A failed test almost always means one of three things: the key was revoked, the key belongs to a different Resend account than the from address, or the from domain isn't verified yet.

Step 03

New message

Everything you type here updates the preview live.

Separate multiple recipients with commas.
Aim for under 60 characters — longer lines get cut off on phones.
PDF or Word documents, up to 35MB total per message.
Step 04

Preview

How the message lands in a recipient's client. Check the sender line and the first two lines of body copy — that's all most people see before deciding.

Inbox
No subject
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No sender configured
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to no recipients yet
Nothing written yet. Head to New message and start typing — this updates as you go.
Step 05

Inbox check

Scores your subject and body against common spam filter triggers before you send it to a real list.

Deep check

Domain report

Checks the DNS records that decide whether mail servers trust your domain — SPF, DKIM, and DMARC — alongside a content pass.

The domain in your from address, without the @ or any path.