# Twilio SendGrid developer documentation

Twilio SendGrid documentation has three main sections:

* Developer documentation (where you are now)
* [User interface (UI) documentation](/docs/sendgrid/ui)
* [API reference](/docs/sendgrid/api-reference)

Developer documentation describes how to implement SendGrid's APIs and developer-focused features.

## Popular developer documentation

### SMTP

* [How to Send an SMTP Email](/docs/sendgrid/for-developers/sending-email/getting-started-smtp)
* [Building an X-SMTPAPI Header](/docs/sendgrid/for-developers/sending-email/building-an-x-smtpapi-header)

### Email API quickstarts

* [C#](/docs/sendgrid/for-developers/sending-email/email-api-quickstart-for-c)
* [Go](/docs/sendgrid/for-developers/sending-email/quickstart-go)
* [Java](/docs/sendgrid/for-developers/sending-email/email-quickstart-for-java)
* [Node.js](/docs/sendgrid/for-developers/sending-email/quickstart-nodejs)
* [PHP](/docs/sendgrid/for-developers/sending-email/quickstart-php)
* [Python](/docs/sendgrid/for-developers/sending-email/quickstart-python)
* [Ruby](/docs/sendgrid/for-developers/sending-email/quickstart-ruby)

### Send with a SendGrid Partner

* [Microsoft Azure](/docs/sendgrid/for-developers/partners/microsoft-azure-2021)

### Templates and dynamic data

* [Personalizations](/docs/sendgrid/for-developers/sending-email/personalizations)
* [Using Handlebars](/docs/sendgrid/for-developers/sending-email/using-handlebars)

### Analytics and reporting

* [Getting Started with the Event Webhook](/docs/sendgrid/for-developers/tracking-events/getting-started-event-webhook)
* [Event Webhook Reference](/docs/sendgrid/for-developers/tracking-events/event)
* [SendGrid Engagement Quality API](/docs/sendgrid/api-reference/sendgrid-engagement-quality-api)

### Parsing email

* [Setting Up the Inbound Parse Webhook](/docs/sendgrid/for-developers/parsing-email/setting-up-the-inbound-parse-webhook)
* [Inbound Parse API](/docs/sendgrid/api-reference/settings-inbound-parse/)

### SDKs and tools

* [C#](https://github.com/sendgrid/sendgrid-csharp)
* [Go](https://github.com/sendgrid/sendgrid-go)
* [Java](https://github.com/sendgrid/sendgrid-java)
* [Node.js](https://github.com/sendgrid/sendgrid-nodejs)
* [PHP](https://github.com/sendgrid/sendgrid-php)
* [Python](https://github.com/sendgrid/sendgrid-python)
* [Ruby](https://github.com/sendgrid/sendgrid-ruby)
* [OpenAPI specification](https://github.com/twilio/sendgrid-oai)

### Glossary

* [Glossary of Terms](/docs/sendgrid/glossary)