Mailgun can be used to send emails in bulk or deliver transactional emails. Transactional emails are triggered after a user's action on the website or app. It can be user registration, forgot password, purchase, etc.
To Simplify Mailgun integration to your website, we create a Mailgun tag for the server Google Tag Manager container that enables you to send transactional emails using customer actions on your site.
Mailgun sGTM tag allows performing two actions: Send an Email or Add/Update a Contact.
API Key - use this link to find info on how to get an API key.
Domain Zone - select if you want to use the US or EU domain zone.
Sending domain - specify your Mailgun sending domain
Add from email to email and email subject.
Add email content - you can use constant or GTM variable.