Clarified comment for SIGNED_ENVELOPED mime state

Author: bbottema

src/main/java/org/simplejavamail/utils/mail/smime/SmimeState.java

@@ -27,7 +27,7 @@ public enum SmimeState {
 
 	/**
 	 * Indicates that the {@link MimePart} or {@link MimeMultipart} is S/MIME
-	 * signed using the older envelope style.
+	 * signed using an envelope (content is wrapped, probably as base64).
 	 */
 	SIGNED_ENVELOPED,