In Outlook, go to File > Account Settings > Account Settings
Under the Email tab, highlight your ADS email account, and click Change
Click on More Settings…
Click on the Connection tab, and then click on Exchange Proxy Settings…
Make sure both of the below boxes are checked.
On fast networks, connect using HTTP first, then connect using TCP/IP
On slow networks, connect using HTTP first, then connect using TCP/IP
Click OK, then you will the below box, click OK
Click Apply > OK
Click Next > Finish > Close
Now, close out of Outlook all the way, and then re-open outlook and it should connect now.