> For the complete documentation index, see [llms.txt](https://docs.mailofly.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.mailofly.com/changelog/email-infrastructure/smtp-providers.md).

# SMTP providers

Mailofly sends through **your** SMTP server — any provider that supports authenticated relay works out of the box.

***

## Supported providers

| Provider               | SMTP host                           | Port       | Username                          |
| ---------------------- | ----------------------------------- | ---------- | --------------------------------- |
| **SendGrid**           | `smtp.sendgrid.net`                 | 587        | `apikey`                          |
| **Mailgun**            | `smtp.mailgun.org` (or regional)    | 587        | `postmaster@yourdomain`           |
| **Amazon SES**         | `email-smtp.{region}.amazonaws.com` | 587        | SMTP credentials from SES console |
| **Postmark**           | `smtp.postmarkapp.com`              | 587        | Server token                      |
| **Brevo (Sendinblue)** | `smtp-relay.brevo.com`              | 587        | Your login email                  |
| **Custom / cPanel**    | Your host's SMTP                    | 587 or 465 | Mailbox or relay user             |

***

## Setup in Mailofly

1. [**Accounts**](https://www.mailofly.com/user/accounts) **→ Add account → SMTP**
2. Enter provider credentials
3. Set **daily mail limit** conservatively (start at 100–500/day)
4. **Send test** to verify
5. Copy the **`acc_…` key** for API compose calls

### Via API

```bash
curl -sS -X POST "https://www.mailofly.com/api/v1/accounts" \
  -H "Authorization: Bearer mf_live_…" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "SendGrid transactional",
    "provider_type": "smtp",
    "smtp_host": "smtp.sendgrid.net",
    "smtp_port": 587,
    "smtp_username": "apikey",
    "smtp_password": "SG.your_api_key",
    "daily_mail_limit": 500
  }'
```

***

## Provider-specific tips

### SendGrid

* Use an **API key** with Mail Send permission as the SMTP password
* Username is always `apikey`
* Set up [domain authentication](https://docs.sendgrid.com/ui/account-and-settings/how-to-set-up-domain-authentication) in SendGrid for best deliverability

### Amazon SES

* Generate **SMTP credentials** (not IAM keys) from the SES console
* Verify your domain in SES **and** in Mailofly [Domains](https://docs.mailofly.com/guides/domains) if using domain relay
* Request production access to leave the SES sandbox

### Mailgun

* Use the SMTP credentials from your Mailgun domain settings
* Regional endpoints matter — match your Mailgun region

***

## SMTP vs domain relay

|                  | SMTP account        | Domain relay                |
| ---------------- | ------------------- | --------------------------- |
| Credentials      | Your ESP SMTP login | Verified domain in Mailofly |
| Sending path     | Direct to your ESP  | Mailofly → Amazon SES       |
| From address     | ESP-dependent       | Your `@domain.com`          |
| Setup complexity | Low                 | Medium (DNS records)        |

Use SMTP when you already have an ESP relationship. Use [domain relay](https://docs.mailofly.com/guides/domains) for fully branded sends managed in Mailofly.

***

## Related

* [Sending accounts](https://docs.mailofly.com/guides/accounts)
* [Domains & DNS](https://docs.mailofly.com/guides/domains)
* [API: Accounts](https://docs.mailofly.com/api/accounts)


---

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