1 files changed, 108 insertions, 0 deletions
diff --git a/vendor/github.com/emersion/go-smtp/backend.go b/vendor/github.com/emersion/go-smtp/backend.go
new file mode 100644
index 0000000..59cea3a
--- /dev/null
+++ b/vendor/github.com/emersion/go-smtp/backend.go
@@ -0,0 +1,108 @@
+package smtp
+
+import (
+	"io"
+)
+
+var (
+	ErrAuthRequired = &SMTPError{
+		Code:         502,
+		EnhancedCode: EnhancedCode{5, 7, 0},
+		Message:      "Please authenticate first",
+	}
+	ErrAuthUnsupported = &SMTPError{
+		Code:         502,
+		EnhancedCode: EnhancedCode{5, 7, 0},
+		Message:      "Authentication not supported",
+	}
+)
+
+// A SMTP server backend.
+type Backend interface {
+	NewSession(c *Conn) (Session, error)
+}
+
+type BodyType string
+
+const (
+	Body7Bit       BodyType = "7BIT"
+	Body8BitMIME   BodyType = "8BITMIME"
+	BodyBinaryMIME BodyType = "BINARYMIME"
+)
+
+// MailOptions contains custom arguments that were
+// passed as an argument to the MAIL command.
+type MailOptions struct {
+	// Value of BODY= argument, 7BIT, 8BITMIME or BINARYMIME.
+	Body BodyType
+
+	// Size of the body. Can be 0 if not specified by client.
+	Size int
+
+	// TLS is required for the message transmission.
+	//
+	// The message should be rejected if it can't be transmitted
+	// with TLS.
+	RequireTLS bool
+
+	// The message envelope or message header contains UTF-8-encoded strings.
+	// This flag is set by SMTPUTF8-aware (RFC 6531) client.
+	UTF8 bool
+
+	// The authorization identity asserted by the message sender in decoded
+	// form with angle brackets stripped.
+	//
+	// nil value indicates missing AUTH, non-nil empty string indicates
+	// AUTH=<>.
+	//
+	// Defined in RFC 4954.
+	Auth *string
+}
+
+// Session is used by servers to respond to an SMTP client.
+//
+// The methods are called when the remote client issues the matching command.
+type Session interface {
+	// Discard currently processed message.
+	Reset()
+
+	// Free all resources associated with session.
+	Logout() error
+
+	// Authenticate the user using SASL PLAIN.
+	AuthPlain(username, password string) error
+
+	// Set return path for currently processed message.
+	Mail(from string, opts *MailOptions) error
+	// Add recipient for currently processed message.
+	Rcpt(to string) error
+	// Set currently processed message contents and send it.
+	//
+	// r must be consumed before Data returns.
+	Data(r io.Reader) error
+}
+
+// LMTPSession is an add-on interface for Session. It can be implemented by
+// LMTP servers to provide extra functionality.
+type LMTPSession interface {
+	// LMTPData is the LMTP-specific version of Data method.
+	// It can be optionally implemented by the backend to provide
+	// per-recipient status information when it is used over LMTP
+	// protocol.
+	//
+	// LMTPData implementation sets status information using passed
+	// StatusCollector by calling SetStatus once per each AddRcpt
+	// call, even if AddRcpt was called multiple times with
+	// the same argument. SetStatus must not be called after
+	// LMTPData returns.
+	//
+	// Return value of LMTPData itself is used as a status for
+	// recipients that got no status set before using StatusCollector.
+	LMTPData(r io.Reader, status StatusCollector) error
+}
+
+// StatusCollector allows a backend to provide per-recipient status
+// information.
+type StatusCollector interface {
+	SetStatus(rcptTo string, err error)
+}