Merge pull request #9 from Ackar/empty-from

Allow empty `FROM`

Author: alash3al

processors.go

@@ -135,25 +135,31 @@ func mailProcessor(req *Request) error {
 		return req.TextProto.PrintfLine("%d %s", 501, "MAIL command contained invalid address")
 	}
 
-	// extraxt the from email address
-	from := emailRegExp.FindStringSubmatch(req.Line[1][i+1:])[1]
-	fromParts := strings.SplitN(from, "@", 2)
+	req.MailFromReceived = true
 
+	// extract the from email address
+	fromParts := emailRegExp.FindStringSubmatch(strings.TrimSpace(req.Line[1][i+1:]))
+
+	from := fromParts[1]
 	req.From = from
-	ip, _, _ := net.SplitHostPort(req.RemoteAddr)
 
-	// check the spf result
-	req.SPFResult, _, _ = spf.CheckHost(net.ParseIP(ip), fromParts[1], from)
+	if from != "" {
+		ip, _, _ := net.SplitHostPort(req.RemoteAddr)
+
+		// check the spf result
+		domain := fromParts[3]
+		req.SPFResult, _, _ = spf.CheckHost(net.ParseIP(ip), domain, from)
 
-	// check the mx records of the from hostname
-	mxs, err := net.LookupMX(fromParts[1])
-	req.Mailable = (err == nil) && len(mxs) > 0
+		// check the mx records of the from hostname
+		mxs, err := net.LookupMX(domain)
+		req.Mailable = (err == nil) && len(mxs) > 0
+	}
 
 	return req.TextProto.PrintfLine("%d %s", 250, "Ok")
 }
 
 func rcptProcessor(req *Request) error {
-	if req.From == "" {
+	if !req.MailFromReceived {
 		return req.TextProto.PrintfLine("%d %s", 503, "Bad sequence of commands")
 	}
 	if len(req.Line) < 2 {
@@ -177,7 +183,7 @@ func rcptProcessor(req *Request) error {
 }
 
 func dataProcessor(req *Request) error {
-	if req.To == nil || req.From == "" || len(req.To) == 0 {
+	if req.To == nil || len(req.To) == 0 || !req.MailFromReceived {
 		return req.TextProto.PrintfLine("%d %s", 503, "Bad sequence of commands")
 	}
 	err := req.TextProto.PrintfLine("%d %s", 354, "End data with <CR><LF>.<CR><LF>")

request.go

@@ -33,6 +33,9 @@ type Request struct {
 	// whether EHLO/HELO called or not
 	HelloRecieved bool
 
+	// whether MAIL FROM was received or not
+	MailFromReceived bool
+
 	// the login username used for login, empty means that this is an anonymous attempt
 	AuthUser string
 
@@ -93,6 +96,7 @@ func (req *Request) Serve() {
 // Reset resets to the defaults
 func (req *Request) Reset() {
 	req.From = ""
+	req.MailFromReceived = false
 	req.To = make([]string, 0)
 	req.Message = nil
 }

vars.go

@@ -36,5 +36,5 @@ var (
 )
 
 var (
-	emailRegExp = regexp.MustCompile(`^<((\S+)@(\S+))>$`)
+	emailRegExp = regexp.MustCompile(`^<((\S+)@(\S+))?>$`)
 )