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Troubleshooting Mailgun Connection Issues

If the standard Mailgun integration isn't connecting, or if you are using a specialized Mailgun setup (like an EU-based account), you should use the SMTP (Other) connection. This allows for a manual, high-precision configuration.

Written by Carmil
Updated this week

⚠️ Special Note for GoHighLevel (GHL) / LC Email Users

If you are using LeadConnector (LC) Email via GoHighLevel, your SMTP settings are different from a standard Mailgun account, even though Mailgun powers the backend.

Do not use the Mailgun integration. Use the SMTP (Other) option and ensure you are using the specific SMTP credentials provided in your GHL "Email Services" tab.

Step 1: Select "SMTP (Other)"

In your Warmbox dashboard, click Add new inbox, but instead of selecting the Mailgun logo, select SMTP (Other) and click Next.

Step 2: Enter your Manual SMTP Details

To connect manually, you will need to input the following four pieces of information:

  1. SMTP Host (Server): * US Region: smtp.mailgun.org

    • EU Region: smtp.eu.mailgun.org

  2. Port: We recommend using 587 (TLS) or 465 (SSL).

  3. SMTP Username: Your Mailgun SMTP login (e.g., [email protected]).

  4. SMTP Password: The specific 16-character SMTP password generated in your Mailgun dashboard.

Find your SMTP credentials here.

Step 3: Test and Connect

Click Check connection. Once the green checkmark appears, click Next to finalize your warm-up settings.

Still not connecting?

  • The #1 reason Mailgun connections fail is a region mismatch. If your Mailgun account was created on the European (EU) server, using the standard smtp.mailgun.org host will fail. Solution: Simply add .eu to the host name: smtp.eu.mailgun.org.

  • Ensure you aren't using your Mailgun API Key by mistake. Warmbox requires the SMTP Password.

  • Ensure your domain is "Active" and "Verified" in Mailgun. If it is still in "Trial" or "Unverified" status, Google and Outlook will likely block the connection.

  • Send us a message via the live chat in the bottom right of your screen or an email at [email protected].

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