GuideIntegrationsClerk

Clerk Integration

Connect Clerk to Simply Send to deliver your application's authentication emails — magic links, verification codes, and password resets — through your own verified sending domain.

Overview

By default, Clerk sends auth emails from its shared IP pool and a generic address. Integrating Simply Send gives you:

Branded Sending Identity

Verification codes and invite emails arrive from [email protected] instead of Clerk's default address.

DMARC & DKIM Compliance

Avoid deliverability issues by sending fully SPF/DKIM authenticated emails from your own domain.

Setup Guide

To integrate Clerk with Simply Send, you'll provision SMTP credentials in Simply Send and copy them into your Clerk dashboard.

1
Provision Credentials in Simply SendGo to the Integrations tab in your User Portal and click Connect on the Clerk card. Customize the credential label and click Create Credentials. Keep this window open.
2
Navigate to Clerk SMTP SettingsLog in to your Clerk Dashboard, select your project, and navigate to Configure → Emails. Scroll down to the SMTP Server section and enable the toggle.

Enter Simply Send SMTP CredentialsEnter the SMTP configurations shown in your Simply Send credential setup popup:

Host:             <smtp-server-from-setup>
Port:             587 (TLS/STARTTLS)
From Address:     [email protected]
Username:         your-generated-username
Password:         your-generated-password

4
Save and VerifyClick Save inside Clerk to establish the connection. Send a test sign-in email from Clerk to confirm everything routes successfully.
5
Add Compliance Variables to Clerk Email TemplatesIn your Clerk Dashboard, navigate to Configure → Emails and edit each email template (sign-in link, magic link, etc.). Paste the following variables into the HTML body — Simply Send will substitute them with your configured unsubscribe link and company address from Templates → Compliance:
```

<div>{{unsubscribe_email_html}}</div>
<div>{{company_address_html}}</div>


<div>{{report_abuse_email_html}}</div>
```
Emails missing these variables will be rejected by Simply Send with a MISSING_TEMPLATE_VARIABLES error.

Troubleshooting

Ensure "From Address" matches

Simply Send requires that the sender address configured in Clerk exactly matches the From Address bound to your Simply Send SMTP credential. If they mismatch, our servers will reject the outgoing email.