How to Send Transactional Emails from a Retool Admin Panel

What is a Retool admin panel, and why send transactional emails from it?

A Retool admin panel is an internal dashboard built in Retool. It gives Ops teams a UI to act on customer data. Sending transactional emails from inside that panel matters for one reason. The trigger lives in the same place that the Ops user is already working.

Transactional emails are responses to a user action. A refund, a status change, a manual approval. They aren’t marketing blasts, even when an Ops user fires them manually.

These are three common Ops-triggered transactional emails:

• Account approval: Ops reviews a sign-up and then sends an approval or rejection notice.
• Refund confirmation: Ops processes a refund and notifies the customer.
• Manual order update: Ops fixes a stuck order and emails the new status.

You can run all three from a single Retool resource that points to SendLayer SMTP.

Prerequisites

You need a Retool account, a verified SendLayer sending domain, and basic familiarity with JavaScript. Here’s the full checklist:

• A Retool workspace (the free plan works for this tutorial).
• A SendLayer account with at least 1 verified sending domain.
• A data source connected in Retool that holds your customer or order records.

What accounts and access do you need?

You need a Retool admin role and an active SendLayer account. The admin role on Retool lets you create resources. The SendLayer account lets you read SMTP credentials. It also lets you add sending domains.

How to get your SendLayer SMTP credentials

In SendLayer, open Settings » SMTP Credentials and copy the host, port, username, and password. To grab the values:

Sign in to your SendLayer account and go to Settings » SMTP Credentials.

Once here, copy the values for Host, Port, Username, and Password.

Keep this tab open. You’ll paste each value into Retool next.

Here’s what you’ll paste into Retool:

How to add SendLayer as an SMTP resource in Retool

In Retool, click the Resources tab at the top-right menu bar. Once there, click the Create new button and select Resource from the dropdown menu.

After that, type “SMTP” in the resource search bar and choose the SMTP option.

Then paste the SendLayer credentials into the form.

After adding the SMTP details, click the Create Resource button.

How do you test the SMTP connection in Retool?

To test the SMTP configuration, click Test Connection at the top-right side of the form.

You should see a green success notification if everything is configured properly. If the test fails:

• Double-check the host (smtp.sendlayer.net, not .com).
• Confirm the port is 587, not 25 or 2525.
• Re-copy the username and password. No trailing whitespace.
• Try port 465 instead if your network blocks 587.

How to build a refund confirmation panel in Retool

This section serves as a practical send email in Retool example. It covers how to trigger transactional emails directly from your admin panel.

Building a refund confirmation panel in Retool often involves three components. Here’s how the pieces connect:

• Table lists orders pulled from your database resource.
• Form shows the customer email, order ID, and a refund-note textarea.
• Button fires the SMTP query, which sends the email through SendLayer.

How to wire a table row to the email form

To connect a table row to the email form, bind each Form input’s Default value to the matching column on the selected table row. Inside the Email input, set the Default value to:

{{ table1.selectedRow.customer_email }}

Inside the Order ID input:

{{ table1.selectedRow.order_id }}

When Ops clicks a row in the table, the Form auto-fills with that customer’s details. The refund-note Textarea remains empty, so ops can type a custom message for each refund.

How to write the SMTP query with dynamic fields

Create a new query against the sendlayer-smtp resource. Reference Form values in the From, To, Subject, and Body fields.

In the bottom-left Code panel, click + » Resource query.

Then choose the SMTP resource you created. In my case, this value is sendlayer-smtp.

Fill in each field as below.

After setting the email subject and dynamic recipient, paste this into the Body field:

<p>Hi {{ first_name.value }},</p>

<p>We've processed a refund for order <strong>#{{ order_id.value }}</strong>. The funds should appear in your account within 5 to 10 business days.</p>

<p>Note from our team:</p>
<blockquote>{{ refund_note.value }}</blockquote>

<p>Reply to this email if anything looks off.</p>

<p>Thanks,<br>Acme Support</p>

How to trigger the email when a user clicks the Send button

Add an event handler to the Submit button that triggers the sendRefundEmail query. Here’s how to configure it:

Select your form’s submit button. In the right panel, click + under Event handlers.

Configure as follows:

• Event: Click.
• Action: Control query.
• Query: your-query-resource.
• Method: Trigger.

Add a second event handler for the same button. Action: Show notification, with a success message.

Why are Retool emails landing in spam, and how do you fix it?

Retool emails land in spam when the From domain isn’t authenticated. SendLayer requires you to add 5 DNS records for domain verification and to improve email deliverability.

If any of your domain’s DNS records are missing, your emails might end up in spam.

For a wider look at the DNS records and authentication signals every sending domain should set, see SendLayer’s email security best practices.

Should you use Retool Email or SendLayer SMTP?

Retool recently launched its email integration. However, it might not be the best fit for your project. As a rule of thumb, use Retool Email for low-volume internal alerts. Use a third-party email provider, such as SendLayer SMTP, for any email a customer will see.

Here’s a table comparing both options.

Other providers, such as SendGrid, also offer SMTP and API-based email delivery, but SendLayer focuses on simpler setup and consistent deliverability for transactional use cases.

Retool Email is fine for internal “the import job finished” alerts. For anything a customer sees, route it through a dedicated provider. Set up proper DNS. That’s the difference between the inbox and the spam folder.

FAQs – Send Email in Retool

Below, we’ve answered some of the top questions developers ask about sending transactional emails from a Retool admin panel.