diff --git a/mailnews/base/util/nsMsgUtils.cpp b/mailnews/base/util/nsMsgUtils.cpp
index ad23c8525efd..102168c46d7f 100644
--- a/mailnews/base/util/nsMsgUtils.cpp
+++ b/mailnews/base/util/nsMsgUtils.cpp
@@ -811,3 +811,29 @@ nsresult MSGCramMD5(const char *text, PRInt32 text_len, const char *key, PRInt32
 
 }
 
+
+// digest needs to be a pointer to a DIGEST_LENGTH (16) byte buffer
+nsresult MSGApopMD5(const char *text, PRInt32 text_len, const char *password, PRInt32 password_len, unsigned char *digest)
+{
+  nsresult rv;
+  unsigned char result[DIGEST_LENGTH];
+  unsigned char *presult = result;
+
+  nsCOMPtr<nsISignatureVerifier> verifier = do_GetService(SIGNATURE_VERIFIER_CONTRACTID, &rv);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+
+  HASHContextStr      *context;
+  PRUint32 resultLen;
+
+  rv = verifier->HashBegin(nsISignatureVerifier::MD5, &context);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = verifier->HashUpdate(context, text, text_len);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = verifier->HashUpdate(context, password, password_len);
+  NS_ENSURE_SUCCESS(rv, rv);
+  rv = verifier->HashEnd(context, &presult, &resultLen, DIGEST_LENGTH);
+  NS_ENSURE_SUCCESS(rv, rv);
+  memcpy(digest, result, DIGEST_LENGTH);
+  return rv;
+}
diff --git a/mailnews/base/util/nsMsgUtils.h b/mailnews/base/util/nsMsgUtils.h
index 31c3d79e6881..8c5b2dc4b341 100644
--- a/mailnews/base/util/nsMsgUtils.h
+++ b/mailnews/base/util/nsMsgUtils.h
@@ -97,5 +97,6 @@ NS_MSG_BASE nsresult GetOrCreateFolder(const nsACString & aURI, nsIUrlListener *
 #define DIGEST_LENGTH 16
 
 NS_MSG_BASE nsresult MSGCramMD5(const char *text, PRInt32 text_len, const char *key, PRInt32 key_len, unsigned char *digest);
+NS_MSG_BASE nsresult MSGApopMD5(const char *text, PRInt32 text_len, const char *password, PRInt32 password_len, unsigned char *digest);
 #endif