> ## Documentation Index
> Fetch the complete documentation index at: https://docs.mailchannels.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Email API vs SMTP

> Learn the differences between the Email API and SMTP, and when to choose each.

## Two ways to send

MailChannels gives you two ways to hand off your mail: the HTTP Email API and SMTP. Both deliver through the same
infrastructure and reach the same inboxes. The difference is how your application connects.

The Email API is an HTTPS interface: your application sends a single request with a JSON body describing the message. SMTP
is the long-established mail protocol: you point an existing mail server or SMTP client at MailChannels and it relays your
mail.

## How they compare

|                   | Email API                                                                          | SMTP                                                               |
| ----------------- | ---------------------------------------------------------------------------------- | ------------------------------------------------------------------ |
| How you integrate | Send an HTTPS request with a JSON body                                             | Point an existing mail server or SMTP client at MailChannels       |
| Connection        | HTTPS request to the Email API at `api.mailchannels.net`                           | Relay through `smtp.mailchannels.net` using SMTP                   |
| Authentication    | API key sent in the `X-Api-Key` header                                             | Account ID and SMTP password using SMTP AUTH                       |
| DKIM signing      | Managed DKIM signing available — MailChannels signs on your behalf once configured | MailChannels does not sign; your own DKIM signatures are preserved |
| Delivery events   | Delivery, bounce, and engagement webhooks                                          | abuse notifications webhooks                                       |

Both methods require the same DNS setup on every sending domain: a [Domain Lockdown](/email-api/domain-lockdown) record
and an [SPF](/email-api/spf-dkim-dmarc) record.

## When to choose the Email API

Choose the Email API if you are:

* Building a new application, or sending from a serverless or edge environment where holding an SMTP connection is awkward.
* Relying on delivery, bounce, and engagement [webhooks](/email-api/webhooks) to track what happens to your mail.

Start with the [Email API quickstart](/email-api/curl/quickstart).

## When to choose SMTP

Choose SMTP if you:

* Already run a mail server, or use software that sends over SMTP, and want to move to MailChannels with little or no code
  change.

See [Sending via SMTP](/email-api/smtp-sending) to get started.