Hundreeds and thousands of Schannel events generated on Exchange 2007

Guys, thousands schannel errors makes my event log look ugly.
Here is what I get:

Log Name:      System
Source:        Schannel
Date:          31/05/2013 16:50:19
Event ID:      36888
Task Category: None
Level:         Error
Keywords:      
User:          SYSTEM
Computer:      EXCHANGE.xxx.co.uk
Description:
The following fatal alert was generated: 10. The internal error state is 10.
Event Xml:
<Event xmlns="http://schemas.microsoft.com/win/2004/08/events/event">
  <System>
    <Provider Name="Schannel" Guid="{1F678132-5938-4686-9FDC-C8FF68F15C85}" />
    <EventID>36888</EventID>
    <Version>0</Version>
    <Level>2</Level>
    <Task>0</Task>
    <Opcode>0</Opcode>
    <Keywords>0x8000000000000000</Keywords>
    <TimeCreated SystemTime="2013-05-31T15:50:19.678337600Z" />
    <EventRecordID>277771</EventRecordID>
    <Correlation />
    <Execution ProcessID="568" ThreadID="1676" />
    <Channel>System</Channel>
    <Computer>EXCHANGE.xxx.co.uk</Computer>
    <Security UserID="S-1-5-18" />
  </System>
  <EventData>
    <Data Name="AlertDesc">10</Data>
    <Data Name="ErrorState">10</Data>
  </EventData>
</Event>

Any ideas how can I find out what is it and how to get rid of it ?

Thanks