1. Introduction

Setting up a professional business email system can be costly, but a combination of Mailgun and Gmail provides a budget-friendly alternative. This setup allows businesses to send and receive emails from their custom domain without the need for expensive email hosting solutions like Google Workspace or Microsoft 365.

This guide outlines how to configure Mailgun and Gmail to manage business emails efficiently.

2. Why Use Mailgun + Gmail?

✅ Low Cost – Mailgun offers a free plan with up to 100 daily emails, and Gmail is free.
✅ Professional Email Address – Send and receive emails from info@yourdomain.com.
✅ High Deliverability – Mailgun provides SPF, DKIM, and DMARC support to prevent spam filtering.
✅ Reliable Inbox Management – Gmail's interface is easy to use with strong spam filtering.
✅ Scalability – Mailgun allows for high-volume email sending when needed.

3. System Overview

The system consists of:

1. Mailgun – Handles sending emails via SMTP and forwarding received emails.
2. Gmail – Acts as the primary inbox for receiving and sending business emails.
3. DNS Configuration – Proper setup of SPF, DKIM, and DMARC records for authentication.

4. Setting Up Mailgun for Sending Emails

Step 1: Register a Mailgun Account

1. Go to Mailgun.com and sign up for a free account.
2. Add and verify your custom domain.

Step 2: Configure DNS Records

Set up the following records in your domain registrar’s DNS settings:

• MX Records (Required for receiving emails via Mailgun forwarding):

  @   MX   10 mxa.mailgun.org
  @   MX   10 mxb.mailgun.org
  

• SPF Record (Authorizes Mailgun to send emails on your behalf):

  v=spf1 include:mailgun.org ~all
  

• DKIM Record (Prevents email spoofing, provided by Mailgun):

  mailo._domainkey TXT "v=DKIM1; k=rsa; p=..."
  

• DMARC Record (Defines email handling policies):

  _dmarc TXT "v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com"
  

Step 3: Configure SMTP for Sending Emails from Gmail

1. Go to Gmail → Settings → Accounts & Import.
2. Under Send mail as, click Add another email address.
3. Enter info@yourdomain.com as the email address.
4. Use the following Mailgun SMTP settings:
   • SMTP Server: smtp.mailgun.org
   • Port: 587 (or 465 for SSL)
   • Username: postmaster@yourdomain.com
   • Password: (Get this from your Mailgun account settings)
5. Verify the email via a confirmation link sent to Gmail.

5. Setting Up Mail Forwarding (Receiving Emails in Gmail)

Since Mailgun does not provide an inbox, you need email forwarding to route emails to Gmail.

Step 1: Configure Mailgun Email Forwarding

1. Go to Mailgun Dashboard → Routes.
2. Create a new rule:
   • Filter Expression: Match recipient (info@yourdomain.com)
   • Action: Forward to yourbusiness@gmail.com
3. Save the rule.

Now, all emails sent to info@yourdomain.com will arrive in your Gmail inbox.

6. Verifying & Testing the Setup

1. Send a test email from another email (e.g., yourname@gmail.com) to info@yourdomain.com and check if it arrives in Gmail.
2. Send an email from Gmail (using Mailgun SMTP) and ensure recipients see info@yourdomain.com as the sender.
3. Check email headers in Gmail to confirm SPF, DKIM, and DMARC pass.

7. Optimizing for Deliverability

✅ Ensure SPF, DKIM, and DMARC records are correctly set up.
✅ Avoid sending too many emails too quickly (Mailgun limits free accounts to 100 emails/day).
✅ Use a professional email signature to increase credibility.
✅ Regularly monitor Mailgun logs to identify any issues.

8. Scaling Up (When to Upgrade Mailgun)

If your email volume grows beyond 100 emails/day, consider:

• Upgrading to Mailgun’s Foundation Plan ($35/month for 50,000 emails/month).
• Using a dedicated IP address to improve reputation.
• Adding more business email addresses (e.g., support@yourdomain.com, sales@yourdomain.com).

9. Conclusion

This Mailgun + Gmail setup provides a budget-friendly, professional email system for small businesses. With proper DNS configurations, SMTP integration, and email forwarding, you can manage business emails efficiently without paying for Google Workspace or dedicated email hosting.