Using Windows 7 with Windows Live Mail, I can synch with my Gmail account.  It will accept incoming mail and send mail. However, my Outlook.com account will not synch at all with WLM.  I tries continuously to synch calendar, but never progresses. I have tried deleting the account from WLM and reinstating it.  The error I get is

Unable to send or receive messages for the Outlook (xxxxxxxxxxx) account.

Server Error: 3204

Server: 'https://mail.services.live.com/DeltaSync_v2.0.0/Sync.aspx'

Windows Live Mail Error ID: 0x8DE20003

I can log into OWA and see all my messages queuing, ready to download.  I can send from OWA.

So, I deduce from the evidence that there is nothing wrong per se with my WLM installation nor with my Outlook.com account. It is a problem with synching between the two only.

I have done a registry scan to no avail.

I have scoured the community discussions and see that similar problems have occurred with different devices and operating systems, but can find no specific solution that helps me.

What else can I try?