Mailgun

Mailgun is an API-based email service. It uses HTTPS (port 443), so it works on every cloud provider without any port-unblocking tickets.

Pricing

• Free — 100 emails/day (first 3 months on the Flex plan).
• Paid — $0.80 per 1,000 emails after the free tier, or from $15/month on fixed plans.

Always verify pricing at https://mailgun.com/pricing — it moves.

Setup

1. Create an account at https://mailgun.com.
2. Add and verify your sending domain (DNS TXT/MX records).
3. Copy your API key from the Mailgun dashboard.

import "github.com/gopackx/go-notification/channel/mail/mailgun"

notifier.RegisterChannel("mail", mailgun.New(mailgun.Config{
    Domain: "mg.example.com",
    APIKey: os.Getenv("MAILGUN_API_KEY"),
    From:   "noreply@example.com",
    Region: "us",
}))

Configuration reference

Sending

Same fluent builder as every other email driver:

func (n OrderShipped) ToMail(u notification.Notifiable) *mail.Message {
    return mail.NewMessage().
        Subject("Your order shipped").
        Line("Hi, your order is on its way.").
        Action("Track package", "https://example.com/track")
}

Webhook events (optional)

Mailgun can POST delivery, open, click, bounce, and complaint events back to you. This is orthogonal to go-notification — configure webhooks in the Mailgun dashboard and handle them in your own HTTP handler. The driver itself only sends.

Troubleshooting

• 401 Unauthorized — wrong API key, or the key is for a different region (US vs. EU).
• Forbidden: domain not found — Domain field doesn't match a verified domain on your account.
• Mail arrives but is flagged spam — verify SPF, DKIM, and DMARC records in the Mailgun domain setup screen. All three matter.
• Free-tier exhausted earlier than expected — the 100/day window resets daily, not monthly.