diff --git a/store/src/java/com/zimbra/cs/mailbox/MailSender.java b/store/src/java/com/zimbra/cs/mailbox/MailSender.java
index 45daa368b40..5c9293d9fa8 100644
--- a/store/src/java/com/zimbra/cs/mailbox/MailSender.java
+++ b/store/src/java/com/zimbra/cs/mailbox/MailSender.java
@@ -1480,6 +1480,13 @@ public static void unregisterPreSendMailListener(PreSendMailListener listener) {
         }
     }
 
+    /**
+     * provide the Hash for Message-Verification header field.
+     * @param id
+     * @param date
+     * @param from
+     * @throws ServiceException
+     */
     public static String getHashForMessageVerification(String id, Date date, String from) throws MessagingException, ServiceException {
         String guid = (id + date + from);
         String guidHash = getEncryptedValue(guid, ALGORITHM_NAME);
@@ -1487,6 +1494,12 @@ public static String getHashForMessageVerification(String id, Date date, String
         return hash;
     }
 
+    /**
+     * provide the Encrypted value of the GUID.
+     * @param input
+     * @param algo
+     * @throws ServiceException
+     */
     public static String getEncryptedValue(String input, String algo) throws ServiceException {
         try {
             MessageDigest md1 = MessageDigest.getInstance(algo);