SMTP Setup

How to Connect Mailgun to GQ CRM (Step-by-Step)

Create a Mailgun domain, find your SMTP credentials, verify DNS, and connect Mailgun to GQ CRM in about 10 minutes.

Published August 1, 2026

Mailgun is a developer-friendly email service that works as an SMTP relay — a good middle ground between raw SES and managed sending. This guide covers creating a Mailgun domain, getting your SMTP credentials, and connecting it to GQ CRM.

1. Create and verify a domain in Mailgun

  1. Sign up at mailgun.com and go to Sending → Domains.
  2. Click Add New Domain and enter the domain you want to send from (e.g. mail.yourcompany.com or your root domain).
  3. Mailgun shows DNS records to add at your DNS provider:
    • SPF TXT record (authorizes Mailgun to send for your domain)
    • DKIM TXT record (signs your mail)
    • MX records (optional, for receiving bounces/feedback)
  4. After adding them, click Verify DNS in Mailgun. Wait for the status to change to Verified.

Deliverability tip: verify SPF and DKIM before sending — mail from an unverified domain is much more likely to land in spam.

2. Find your SMTP credentials

  1. In Mailgun, go to Sending → Domains → your domain.
  2. The SMTP section shows:
    • Host: smtp.mailgun.org
    • Port: 587 (STARTTLS) or 465 (SSL)
    • Default SMTP Login: usually postmaster@<your-domain>.mailgun.org
    • Default Password: shown when you click "Reset Password" (or use the account's Master Password from the Account settings)
  3. Copy the login and password.

3. Connect Mailgun to GQ CRM

  1. Log in to GQ CRM and open Projects → your project → SMTP Configuration.
  2. Fill in the fields:
FieldValue
SMTP Hostsmtp.mailgun.org
Port587 (STARTTLS) or 465 (SSL)
Secure connectionOn
Auth userYour Mailgun SMTP login (e.g. [email protected])
Auth passwordYour Mailgun SMTP password
From nameYour name or brand
From emailAn address at your verified domain
  1. Click Test connection.
  2. Save and send a test email to confirm.

4. Know Mailgun's limits

  • Mailgun's free trial includes a sandbox domain (only for testing to authorized recipients) — always create your own verified domain for real sending.
  • Standard plans include a monthly email quota; overage is billed per thousand. Keep an eye on it if you run large campaigns.
  • Mailgun adds a Received header and routes through its own IP pools — reputation is shared unless you pay for dedicated IPs. Pace your volume with GQ CRM's rate limits.

Troubleshooting

  • 535 Authentication failed — wrong SMTP login/password; use the domain's SMTP login, not your Mailgun dashboard password.
  • Sandbox restriction error — you're sending from the sandbox domain; create and verify your own domain (step 1).
  • Delays or throttling — Mailgun queues during spikes; lower your task rate limit to stay within your plan's throughput.
  • SPF/DKIM not aligned — re-check the DNS records from step 1 and wait for propagation.