internal/protocol

Implementation of https://www.rfc-editor.org/rfc/rfc5321.html

Types

Action

Represents the next action to take in the SMTP protocol state machine.

Send(cmd, next): Send an SMTP command, then continue with next.
Receive(callback): Wait for an SMTP response, then call callback.
Upgrade(next): Upgrade the connection to TLS, then continue with next.
Done: The protocol session has completed successfully.

pub type Action {
  Send(String, fn() -> Result(Action, ProtocolError))
  Receive(fn(String) -> Result(Action, ProtocolError))
  Upgrade(fn() -> Result(Action, ProtocolError))
  Done
}

Constructors

Send(String, fn() -> Result(Action, ProtocolError))

Receive(fn(String) -> Result(Action, ProtocolError))

Upgrade(fn() -> Result(Action, ProtocolError))

```
Done
```

ArgumentError

</>

pub type ArgumentError {
  EncodingError(encoding.EncoderError)
  InvalidAddress(String)
  NoFromMailboxSpecified
  NoRecipientsSpecified
  DataSizeError(actual: Int, allowed: Int)
  DataRenderError(internet_message.RenderError)
}

Constructors

```
EncodingError(encoding.EncoderError)
```
```
InvalidAddress(String)
```
```
NoFromMailboxSpecified
```
```
NoRecipientsSpecified
```

DataSizeError(actual: Int, allowed: Int)

DataRenderError(internet_message.RenderError)

ProtocolConfig

</>

Configuration for an SMTP protocol session.

helo_host: The hostname to use in the EHLO/HELO command.
credentials: Optional SMTP authentication credentials.

pub type ProtocolConfig {
  ProtocolConfig(
    helo_host: String,
    credentials: option.Option(#(String, String)),
  )
}

Constructors

ProtocolConfig(
  helo_host: String,
  credentials: option.Option(#(String, String)),
)

ProtocolError

</>

Errors that can occur during SMTP protocol communication.

pub type ProtocolError {
  InvalidResponse(response: String)
  UnexpectedResponseCode(expected: Int, actual: Int)
  InvalidRequestError(ArgumentError)
}

Constructors

```
InvalidResponse(response: String)
```

UnexpectedResponseCode(expected: Int, actual: Int)

```
InvalidRequestError(ArgumentError)
```

ReceiveCallback

</>

Callback type for the Receive action. Called with the server response.

pub type ReceiveCallback =
  fn(String) -> Result(Action, ProtocolError)

SendCallback

</>

Callback type for the Send action. Called after a command is sent.

pub type SendCallback =
  fn() -> Result(Action, ProtocolError)

Values

start_session

</>

pub fn start_session(
  message message: message.Message,
  config config: ProtocolConfig,
) -> Result(Action, ProtocolError)

Start an SMTP protocol session for sending a message.

Executes the full SMTP session: server greeting, EHLO/HELO, STARTTLS, authentication (if configured), and mail transaction (MAIL FROM, RCPT TO, DATA).

message: The sendr/message.Message to deliver.
config: The ProtocolConfig for the session.

Returns an Action representing the first action in the protocol sequence.