Mailgun is an email service provider that allows you to send emails through their API. When using Mailgun, you can specify a custom sender domain, which is the domain from which your emails will appear to be sent. This domain must be verified and added to your Mailgun account before you can use it as the sender domain.

Here's how you can set up a custom sender domain in Mailgun:

  1. Sign up for a Mailgun Account: If you haven't already, sign up for a Mailgun account at Once you have an account, log in to the Mailgun dashboard.

  2. Add and Verify Your Domain: In the Mailgun dashboard, go to the "Domains" section and click on "Add New Domain." Enter your domain name (e.g., and follow the instructions to verify ownership of the domain. Mailgun will provide you with DNS records that you need to add to your domain's DNS settings.

  3. Configure Your Sender Domain: After verifying your domain, go to the "Sending" section in the Mailgun dashboard. Under "Sending Domains," you should see your newly added and verified domain. Click on the domain to configure it.

  4. Set Up DNS Records: Follow the instructions provided by Mailgun to add the required DNS records to your domain's DNS settings. These DNS records are used to authorize Mailgun to send emails on behalf of your domain.

  5. Update Mailgun API Settings: In your application code (e.g., in a backend server or using a library that interacts with the Mailgun API), you will need to set the "from" field with an email address from your custom sender domain. The email address should be in the format "".

For example, if you are using the Mailgun API with Node.js, you might do something like this:

const mailgun = require('mailgun-js')({ apiKey: 'YOUR_MAILGUN_API_KEY', domain: '' // Use your custom sender domain }); const data = { from: '', to: '', subject: 'Hello', text: 'Testing Mailgun!' }; mailgun.messages().send(data, (error, body) => { console.log(body); });

That's it! You should now be able to send emails using your custom sender domain through the Mailgun API. Remember to follow Mailgun's guidelines for sending emails and adhere to their terms of service to ensure successful delivery and avoid potential issues.

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