Event id 24 msexchange web services
Once you have done that you should get yourself up to date as that fixes a number of issues. If you are still having issues then then re-post with your errors not some from the Internet which may be subtly different.
SO i increased them with the help of a microsoft article. I have exchange server 2007 SP1 which is running on SBS 2008.It is as follows Event Type: Warning Event Source: MSExchange Web Services Event Category: Core Event ID: 6 Date: Time: User: N/A Computer: SERVER Description: Unable to send a notification for subscription Fw Bzcn Zle GMw My5h YXMua XRz Lm5q YS5kax AAAAB2u1k3cm LBQJP2Si WXm T9t.