I reinstalled my PC with Windows 8.1 RTM bits. The Mail app connects fine to my Outlook.com account (running on a custom domain).  When I install Outlook 2013 however it is no longer able to connect. This was working fine prior to reinstalling my machine from what I recall. It looks like in the past few weeks there have been some EAS issues with Outlook.com so I'm not sure if this is related but since this is the only support channel offered by Microsoft I thought I would add in my report.

After installing Outlook 2013 I followed the guidance on setting up an Outlook.com account. This has worked flawlessly many times before. This time it does not want to accept my credentials:



Using Fiddler I can see the call to the server is returning an HTTP 401 Unauthorized as well:

POST /Microsoft-Server-ActiveSync?Cmd=FolderSync&User=*** Email address is removed for privacy ***&DeviceId=4BB0759DD9A74D9EA1B032913059EF50&DeviceType=WindowsOutlook15 HTTP/1.1
Connection: Keep-Alive
Content-Type: application/vnd.ms-sync.wbxml
Accept-Encoding: gzip, deflate
User-Agent: Outlook/15.0 (15.0.4517.1504; MSI; x86)
MS-ASProtocolVersion: 14.0
X-MS-WL: Outlook/1.0
X-TransactionID: {19971586-D14A-4079-99B8-38CBACB2E72A}
Content-Length: 13
Host: www.outlook.com
Authorization: Basic ---password hash removed---

The password is 100% absolutely correct.  I have typed it out in Notepad, copied and pasted into the field to verify that there is no typo.  Because the Microsoft account behind this also has two-step authentication enabled I have also tried creating another app password but that also fails with the same error.

To summarize:

• Connected to Outlook.com account on my Windows Phone 8, Windows 8.1 Mail app, but cannot connect using Outlook 2013 on Windows 8.1 (RTM)
• Unauthorized error returned from server
• Same process worked previously while running on Windows 8, Windows 8.1 Preview
• Tried using "www.outlook.com", "m.hotmail.com", "s.outlook.com", and "snt-m.hotmail.com" as server addresses
• Have gone to the service status page and reported problems signing in and syncing email even though it feels sometimes like those reports get routed to /dev/null
  

Anyone else having issues connecting to Outlook.com using Outlook desktop client?