Mobile Active Sync problems Error 0x8501001

Try these 2 attempts

http://pdaphonehome.com/forums/ppc-6700-xv6700/76163-cannot-get-6700-sync-exchange-server-error-0x8501001.html

Added port 22675 on firewall and tested https://yourcompany.com/owa on mobile device certificate accepted OK still same error message on this one phone.

You shouldn't need to open any other ports, so close that additional port. This feature is designed to run through port 443.

When you browse to the site, do you get a certificate prompt? If you do then that is a hard failure.

Use a test account on the Microsoft test site:
https://testexchangeconnectivity.com/

Simon.

443 is enabled - we are not using SSL for the moment
All the phones are configured the same only this one user account doesn't work on any phone so I'm quite sure its server side.

443 is SSL. You cannot use port 443 without using SSL.

Furthermore, trying to configure Exchange 2007 without SSL is not a good idea. The entire product is built around web services, and includes a self generated SSL certificate. However that self generated certificate is not supported for use with ActiveSync.

You should finish off the deployment of Exchange 2007 by changing the self generated certificate for a commercial certificate. You will have much less problems if you do that.

Simon.

Thanks for that any ideas what could have happened to the one user account in Exchange?

Not really.
Single user account issues I do little troubleshooting with. Once it is shown to be a single account, if the problem doesn't jump out (ActiveSync disabled for example) then I just recreate the account.

Simon.

Thats my last option as I'll have to backup the profile and emails and rebuild the account, this must be something straight forward on the Exchange server

Not necessarily. It could be something deep within the account configuration. If it was a server issue then it would be affecting all the users.

Simon.

Sorry badly worded yes absolutly something to do with the account on Exchange 2k7

I presume that you have tried a different account on the same device? If that works then a replacement account created. I don't tend to delete old accounts, I prefer to move all content and then hide the old one and put a forward on it to the new account. That way nothing internal is lost when people reply to old emails.

Simon.