smtpssl

Documentation

Index

• func Dial(addr string) (*Client, *ByteLogger, error)
• func NewClient(conn net.Conn, host string) (*Client, *ByteLogger, error)
• func SendMail(addr string, aplain Auth, acram Auth, from string, to []string, msg []byte) ([]byte, error)
• func SendMailSSL(addr string, aplain Auth, acram Auth, from string, to []string, msg []byte) ([]byte, error)
• type Auth
  • func CRAMMD5Auth(username, secret string) Auth
  • func PlainAuth(identity, username, password, host string) Auth
• type ByteLogger
  • func (w *ByteLogger) Write(p []byte) (int, error)
• type Client
  • func (c *Client) Auth(a Auth) error
  • func (c *Client) Data() (io.WriteCloser, error)
  • func (c *Client) Extension(ext string) (bool, string)
  • func (c *Client) Mail(from string) error
  • func (c *Client) Quit() error
  • func (c *Client) Rcpt(to string) error
  • func (c *Client) Reset() error
  • func (c *Client) StartTLS(config *tls.Config) error
  • func (c *Client) Verify(addr string) error
• type ServerInfo

Functions

func Dial

func Dial(addr string) (*Client, *ByteLogger, error)

Dial returns a new Client connected to an SMTP server at addr.

func NewClient

func NewClient(conn net.Conn, host string) (*Client, *ByteLogger, error)

NewClient returns a new Client using an existing connection and host as a server name to be used when authenticating.

func SendMail

func SendMail(addr string, aplain Auth, acram Auth, from string, to []string, msg []byte) ([]byte, error)

SendMail connects to the server at addr, switches to TLS if possible, authenticates with mechanism a if possible, and then sends an email from address from, to addresses to, with message msg.

func SendMailSSL

func SendMailSSL(addr string, aplain Auth, acram Auth, from string, to []string, msg []byte) ([]byte, error)

SendMailSSL does essentially the same thing as SendMail, differing in that it connects over an explicit TLS channel instead of trying STARTTLS.

Types

type Auth

type Auth interface {
	// Start begins an authentication with a server.
	// It returns the name of the authentication protocol
	// and optionally data to include in the initial AUTH message
	// sent to the server. It can return proto == "" to indicate
	// that the authentication should be skipped.
	// If it returns a non-nil error, the SMTP client aborts
	// the authentication attempt and closes the connection.
	Start(server *ServerInfo) (proto string, toServer []byte, err error)

	// Next continues the authentication. The server has just sent
	// the fromServer data. If more is true, the server expects a
	// response, which Next should return as toServer; otherwise
	// Next should return toServer == nil.
	// If Next returns a non-nil error, the SMTP client aborts
	// the authentication attempt and closes the connection.
	Next(fromServer []byte, more bool) (toServer []byte, err error)
}

Auth is implemented by an SMTP authentication mechanism.

func CRAMMD5Auth

func CRAMMD5Auth(username, secret string) Auth

CRAMMD5Auth returns an Auth that implements the CRAM-MD5 authentication mechanism as defined in RFC 2195. The returned Auth uses the given username and secret to authenticate to the server using the challenge-response mechanism.

func PlainAuth

func PlainAuth(identity, username, password, host string) Auth

PlainAuth returns an Auth that implements the PLAIN authentication mechanism as defined in RFC 4616. The returned Auth uses the given username and password to authenticate on TLS connections to host and act as identity. Usually identity will be left blank to act as username.

type ByteLogger

type ByteLogger struct {
	// contains filtered or unexported fields
}

ByteLogger is a simple struct holding the smtp protocol log in smtplog []byte.

func (*ByteLogger) Write

func (w *ByteLogger) Write(p []byte) (int, error)

type Client

type Client struct {
	// Text is the textproto.Conn used by the Client. It is exported to allow for
	// clients to add extensions.
	Text *textproto.Conn
	// contains filtered or unexported fields
}

A Client represents a client connection to an SMTP server.

func (*Client) Auth

func (c *Client) Auth(a Auth) error

Auth authenticates a client using the provided authentication mechanism. A failed authentication closes the connection. Only servers that advertise the AUTH extension support this function.

func (*Client) Data

func (c *Client) Data() (io.WriteCloser, error)

Data issues a DATA command to the server and returns a writer that can be used to write the data. The caller should close the writer before calling any more methods on c. A call to Data must be preceded by one or more calls to Rcpt.

func (*Client) Extension

func (c *Client) Extension(ext string) (bool, string)

Extension reports whether an extension is support by the server. The extension name is case-insensitive. If the extension is supported, Extension also returns a string that contains any parameters the server specifies for the extension.

func (*Client) Mail

func (c *Client) Mail(from string) error

Mail issues a MAIL command to the server using the provided email address. If the server supports the 8BITMIME extension, Mail adds the BODY=8BITMIME parameter. This initiates a mail transaction and is followed by one or more Rcpt calls.

func (*Client) Quit

func (c *Client) Quit() error

Quit sends the QUIT command and closes the connection to the server.

func (*Client) Rcpt

func (c *Client) Rcpt(to string) error

Rcpt issues a RCPT command to the server using the provided email address. A call to Rcpt must be preceded by a call to Mail and may be followed by a Data call or another Rcpt call.

func (*Client) Reset

func (c *Client) Reset() error

Reset sends the RSET command to the server, aborting the current mail transaction.

func (*Client) StartTLS

func (c *Client) StartTLS(config *tls.Config) error

StartTLS sends the STARTTLS command and encrypts all further communication. Only servers that advertise the STARTTLS extension support this function.

func (*Client) Verify

func (c *Client) Verify(addr string) error

Verify checks the validity of an email address on the server. If Verify returns nil, the address is valid. A non-nil return does not necessarily indicate an invalid address. Many servers will not verify addresses for security reasons.

type ServerInfo

type ServerInfo struct {
	Name string   // SMTP server name
	TLS  bool     // using TLS, with valid certificate for Name
	Auth []string // advertised authentication mechanisms
}

ServerInfo records information about an SMTP server.