---
title: "mailComposeSessionDidBegin(_:)"
framework: mailkit
role: symbol
role_heading: Instance Method
path: "mailkit/mecomposesessionhandler/mailcomposesessiondidbegin(_:)"
---

# mailComposeSessionDidBegin(_:)

Informs the handler when the user opens a compose window.

## Declaration

```swift
func mailComposeSessionDidBegin(_ session: MEComposeSession)
```

## Parameters

- `session`: The compose session that corresponds to the message the user is composing.

## See Also

### Handling Compose Sessions

- [MEComposeSession](mailkit/mecomposesession.md)
- [mailComposeSessionDidEnd(_:)](mailkit/mecomposesessionhandler/mailcomposesessiondidend(_:).md)
- [MEComposeSessionError](mailkit/mecomposesessionerror.md)