diff --git a/comp/src/gb.net.smtp/.src/Main.module b/comp/src/gb.net.smtp/.src/Main.module
index be8a7b665..44bad0024 100644
--- a/comp/src/gb.net.smtp/.src/Main.module
+++ b/comp/src/gb.net.smtp/.src/Main.module
@@ -18,9 +18,27 @@ Public Sub Main()
   ' hClient.Add(File.Load("~/TexteDehorsilpleut.odt"), "application/vnd.oasis.opendocument.text", "Dehors il pleut.odt")
   ' hClient.Add(File.Load("~/balloon.png"), "image/png", "balloon.png")
   ' hClient.Send
-
+  
   Dim hMsg As New SmtpClient
   
+  ' Dim sChallenge As String
+  ' Dim sKey As String
+  ' Dim sCommand As String
+  ' Dim sResult As String
+  ' 
+  ' sChallenge = "'abc'"
+  ' sKey = "benoit"
+  ' 
+  ' sCommand = "echo -n " & Shell$(sChallenge) & " | openssl md5 -hmac " & Shell$(sKey)
+  ' Shell sCommand To sResult
+  ' Print sResult
+  ' 
+  ' sCommand = "openssl md5 -hmac " & Shell$(sKey) & " << EOF\n'abc'"
+  ' Shell sCommand To sResult
+  ' Print sResult
+  ' 
+  ' Return
+  
   hMsg.Debug = True
   hMsg.To.Add("benoit@minisini.fr")
   hMsg.Subject = "Test mail headers 5"
diff --git a/comp/src/gb.net.smtp/.src/SmtpClient.class b/comp/src/gb.net.smtp/.src/SmtpClient.class
index 1332bdcf8..2357e8aea 100644
--- a/comp/src/gb.net.smtp/.src/SmtpClient.class
+++ b/comp/src/gb.net.smtp/.src/SmtpClient.class
@@ -309,21 +309,55 @@ Catch
 End
 
 Private Sub Authenticate()
-  
-  Dim sData As String
-  
+
+  Dim sChallenge64, sChallenge, sKey, sCommand, sResponse, sDigestHex As String
+
   If Not $sUser Then Return
-  
-  sData = $hSession.Send("AUTH PLAIN")
-  If $hSession.LastCode <> "334" Then Error.Raise("Unsupported authentication method")
-  
-  sData = $hSession.Send(Base64$($sUser & Chr$(0) & $sUser & Chr$(0) & $sPassword), True)
-  If $hSession.LastCode <> "235" Then Error.Raise("Authentication failed")
-  
+
+  ' AUTH LOGIN
+  $hSession.Send("AUTH LOGIN")
+  If $hSession.LastCode = "334" Then
+    $hSession.Send(Base64$($sUser))
+    If $hSession.LastCode = "334" Then
+      $hSession.Send(Base64$($sPassword))
+      If $hSession.LastCode = "235" Then Return
+    Endif
+  Endif
+
+  ' AUTH PLAIN
+  $hSession.Send("AUTH PLAIN")
+  If $hSession.LastCode <> "334" Then
+    $hSession.Send("AUTH PLAIN " & Base64$($sUser & Chr$(0) & $sUser & Chr$(0) & $sPassword), True)
+  Else
+    $hSession.Send(Base64$($sUser & Chr$(0) & $sUser & Chr$(0) & $sPassword), True)
+  Endif
+  If $hSession.LastCode = "235" Then Return
+
+  ' CRAM-MD5
+  $hSession.Send("AUTH CRAM-MD5")
+  'If $hSession.LastCode = "334" Then Print "LastAnswer = "; $hSession.LastAnswer
+
+  sChallenge64 = Split($hSession.LastAnswer, " ")[1]
+  sChallenge = UnBase64(sChallenge64)
+  sKey = $sPassword
+
+  'sCommand = "echo -n " & Shell$(sChallenge) & " | openssl md5 -hmac " & Shell$(sKey)
+  sCommand = "openssl md5 -hmac " & Shell$(sKey) & " << EOF\n" & sChallenge
+  Shell sCommand To sDigestHex
+
+  sDigestHex = Trim(Split(sDigestHex, "=")[1])
+  sResponse = Base64($sUser & sDigestHex)
+
+  $hSession.Send(sResponse)
+  If $hSession.LastCode = "235" Then Return
+
+  ' Nothing worked?
+  Error.Raise("Authentication failed")
+
 Catch
-  
+
   Error.Raise("Unable to authenticate: " & Error.Text)
-  
+
 End
 
 Private Sub SendRecipients()