From 95ed425097e7d9eb39b596bff383c25b4422348a Mon Sep 17 00:00:00 2001
From: Christian Joergensen <christian.joergensen@gmta.info>
Date: Thu, 17 Jul 2014 16:49:58 +0200
Subject: [PATCH] Reset envelope on duplicate HELO/EHLO and after DATA.

---
 protocol.go | 24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

diff --git a/protocol.go b/protocol.go
index 4a17c8e..f77512c 100644
--- a/protocol.go
+++ b/protocol.go
@@ -93,6 +93,11 @@ func (session *session) handleHELO(cmd command) {
 		return
 	}
 
+	if session.peer.HeloName != "" {
+		// Reset envelope in case of duplicate HELO
+		session.envelope = nil
+	}
+
 	session.peer.HeloName = cmd.fields[1]
 
 	if session.server.HeloChecker != nil {
@@ -116,6 +121,11 @@ func (session *session) handleEHLO(cmd command) {
 		return
 	}
 
+	if session.peer.HeloName != "" {
+		// Reset envelope in case of duplicate EHLO
+		session.envelope = nil
+	}
+
 	session.peer.HeloName = cmd.fields[1]
 
 	if session.server.HeloChecker != nil {
@@ -152,6 +162,11 @@ func (session *session) handleMAIL(cmd command) {
 		return
 	}
 
+	if session.envelope != nil {
+		session.reply(502, "Duplicate MAIL")
+		return
+	}
+
 	addr, err := parseAddress(cmd.params[1])
 
 	if err != nil {
@@ -228,8 +243,8 @@ func (session *session) handleSTARTTLS(cmd command) {
 		return
 	}
 
-	// Reset HeloName as a new EHLO/HELO is required after STARTTLS
-	session.peer.HeloName = ""
+	// Reset envelope as a new EHLO/HELO is required after STARTTLS
+	session.envelope = nil
 
 	// Reset deadlines on the underlying connection before I replace it
 	// with a TLS connection
@@ -270,12 +285,15 @@ func (session *session) handleDATA(cmd command) {
 		// Accept and deliver message
 
 		session.envelope.Data = data.Bytes()
+
 		if err := session.deliver(); err != nil {
 			session.error(err)
 		} else {
 			session.reply(250, "Thank you.")
 		}
 
+		session.envelope = nil
+
 	}
 
 	if err != nil {
@@ -296,6 +314,8 @@ func (session *session) handleDATA(cmd command) {
 		session.server.MaxMessageSize,
 	))
 
+	session.envelope = nil
+
 	return
 
 }