The Waitlist module enables your customers to sign up to an email waitlist for out-of-stock or on-backorder products.
Once the stock status of a product changes to ‘Out of stock’ or ‘On backorder’ in WooCommerce (you can update the status either manually or using WooCommerce’s stock tracker functionality), a waitlist signup form replaces the add-to-cart button on the product page until the product becomes available again.
Merchant Pro will automatically send the subscribers an email notification when the product is back in stock.
In the screenshot below, you can see an example of Merchant Pro’s Waitlist module on a WooCommerce product page (for the example below, we used the free Beauty demo of our Botiga theme):

Note that by default, Merchant Pro will only show the waitlist signup form for out-of-stock products (however, there’s an option in the module’s settings where you can enable the module for on-backorder products, too):

You can set the stock status of a product to ‘out of stock’ on its WooCommerce product page.
To do so, scroll down to the Product data section, open the Inventory tab, and change the Stock status option to ‘Out of stock’.
You can also make WooCommerce track your stock quantity automatically by checking the ‘Track stock quantity for this product’ checkbox:

Now let’s see how you can configure and enable Merchant Pro’s Waitlist module.
1. Open the Waitlist Module
Open your Merchant dashboard by clicking the Merchant menu in the left sidebar of your WordPress admin area.
Under the Boost Revenue heading, click the Waitlist module to open its settings page:

2. Configure the Form Settings
On the admin page of the Waitlist module, you’ll find three groups of settings:
- form settings
- email settings
- shortcode settings (for developers)
First, let’s see the form settings.
Find the Form Settings section and configure the following options:
- Display on backorders? – Here, you can enable the waitlist for backorders (in this case, the waitlist form will appear on the product pages of both out-of-stock and on-backorder products).
- Form title – This is the text that Merchant Pro will show above the waitlist signup form.
- Form email label – Here, you can set up a placeholder text shown inside the input field (e.g. ‘Your Email Address’).
- Form button text – This is the label of the signup button (e.g. ‘Notify Me’).
- Form success message – This is the message that Merchant Pro will show your customers on your website right after they submit the form.

Once the form settings are configured, click the Save button in the top-right corner of the page.
3. Customize the Email Settings
You can find the Email Settings right under the Form Settings.
Merchant Pro will email your subscribers twice:
- New subscriber email (automated):
- Waitlist subscribers receive it when they sign up for the notification.
- Merchant Pro sends the signup email automatically as soon as a customer clicks the ‘Notify Me’ button.
- Stock update email (manual or automated):
- Waitlist subscribers receive it when the product is back in stock.
- You can either send the stock update emails manually or set up Merchant Pro to send them automatically when the status of the product changes to ‘In stock’ on the WooCommerce product page.
In the Email Settings section, you get access to the following options:
- Send emails automatically – This option allows you to set whether you want to send the stock update emails manually or automatically.
- Email new subscribers – Here, you can compose the text of the new subscriber email message. The ‘Click here to preview the new subscriber email.’ option lets you preview the message.
- Email in-stock update – Here, you can compose the text of the stock update email message. The ‘Click here to preview the stock update email.’ option lets you preview the message.

Once the email settings are configured, click the Save button in the top-right corner of the page.
4. Enable the Waitlist Module
To activate the module, click the Enable button at the top of the page:

5. Send the Stock Update Emails
You can send the stock update emails either automatically or manually. You can toggle between the two options in the Email Settings (see above, in Step 3).
i. Set Up Automatic Stock Update Emails (recommended)
If you have the ‘Send emails automatically’ option toggled on in the module’s Email Settings, Merchant Pro will email the subscribers automatically once the status of the product changes to ‘In stock’ on the WooCommerce product page.
iI. Send the Stock Update Emails Manually
Click the Products > Wait List Subscribers option in the left sidebar of your WordPress admin area.
Here, you can find the list of the subscribers. Check the subscribers you want to send the stock update email, click the Bulk actions dropdown at the top of the page, select the Send Email option, and then click the Apply button.
Once you click the Apply button, Merchant Pro emails the selected customers:

6. Set Up an SMTP Plugin instead of Using WooCommerce’s Default Mailer Function (optional)
By default, Merchant Pro uses WooCommerce’s built-in mailer()
method (powered by the PHPMailer library) to send emails from the platform.
However, as the default mailer can sometimes be unreliable, Merchant Pro allows you to send the emails using SMTP (Simple Mail Transfer Protocol).
To send emails with SMTP from a WordPress site, you’ll need to:
- either (and this is method we recommend for most users) install an SMTP plugin such as Post SMTP or WP Mail SMTP – These plugins give you access to the email logs so that you can see which email was sent and which wasn’t (if you want to access the email logs for free, we recommend the Post SMTP plugin).
- or configure the SMTP settings manually
In both cases, you’ll need to sign up for an email API that provides SMTP functionality such as the Gmail API, SendGrid API, Mailjet API, or another one (note that you don’t have to write any code; you only need to insert the API key or ID into the settings of the SMTP plugin).
In the screenshot below, you can see an example of the Post SMTP plugin configured with the SendGrid API:

And here’s what the email logs recorded by Post SMTP look like (they show the details of all the emails that have been sent from your WordPress site):

If you’d rather use WP Mail SMTP (although here, you’ll need the Pro version to access the logs), below you can see an example of how it’s configured with the Gmail API:

Once the SMTP plugin is configured, Merchant Pro will automatically use it to email your waitlist subscribers; you don’t need to change anything else on the module’s admin page.
7. Enable the Waitlist Shortcode (for Developers)
You can find a third group of settings on the module’s admin page under the ‘Use shortcode’ heading.
Here, you can enable the [merchant_module_wait_list]
shortcode that you can use to display the waitlist signup form in a custom location on your WordPress site.
After changing the ‘Use shortcode’ option, click the Save button in the top-right corner of the page:

Video Walkthrough
Check out the video below for a live demo of the Waitlist module: