The last time I ran into a few problems with Activesync and Exchange 2010.
First, Activesync with Exchange 2010 doesn’t work when you have an admin account. You get a strange error (HTTP Options not allowed). Remove your account from the domain admins group for example and it should be working fine.
Activesync still not working? One customer changed the default domain policy. The following settings are important :
Still not working ?
Open dsa.msc (Active Directory Users and computers). Enable the advanced option under view.
Now check out the properties of the account who is trying to sync.
Select Security / Advanced.
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