Fix: Use AND matching for match-rules

Signed-off-by: Knut Ahlers <knut@ahlers.me>

handler.go

@@ -21,14 +21,22 @@ type mailHandler struct {
 }
 
 func (m mailHandler) Handles(msg *enmime.Envelope) bool {
-	for _, ma := range m.Match {
-		if ma.Match(msg) {
-			return true
-		}
-	}
+	if len(m.Match) == 0 {
+		// No matcher available: Should not match anything
 		return false
 	}
 
+	// Do an AND matching: As soon as one matcher fails the whole match fails
+	for _, ma := range m.Match {
+		if !ma.Match(msg) {
+			return false
+		}
+	}
+
+	// None has failed: It matches
+	return true
+}
+
 func (m mailHandler) Process(imapClient *client.Client, msg *imap.Message, envelope *enmime.Envelope) error {
 	cmd := exec.Command(m.Command[0], m.Command[1:]...)
 	cmd.Stderr = os.Stderr