I have had an HTC Sensation for almost 3 years now with multiple email accounts linked to the device (Gmail, Yahoo, and hotmail).  All have worked flawlessly until last week, where my hotmail account does not allow me to send messages from my phone.  I still receive emails and it updates regularly, but will not send anything.  I have attempted to reconfigure the settings, and sign in again, but it keeps giving me an authentication error message.  Which is odd considering I remain signed in, and receive mail.  

Thoughts on correcting this?

Thanks
I recently was forced to accept a Samsung Galaxy 4G as an insurance replacement for my lost HTC Sensation.  Outlook.com was installed on the HTC and functioned without issue.

On the Samsung, Outlook.com reports that "HTML is not supported" and displays the message as plain text.

If I use Outlook.com to forward the email to my gmail.com account all works fine.  Outlook.com on android appears to have and issue.  I;ll try here before taking the app off my phone.

Thanks
My Hotmail account has stopped working on my HTC Sensation phone. T-Mobile is saying I need to get the incoming/outgoing email server settings in order to do a manual setup