ContributionsMost RecentMost LikesSolutionsRe: Outlook 2016 continually prompts for username and password constantly and will not sync This is not an Outlook Problem. I have two email accounts set up with Cox. My wife also has two email accounts. I get the problem on only on email account. My wife does not have the problem at all. I also have an android phone and an android tablet. I have the problem on all devices. My Windows 10 PC with Outlook 2013 and both my phone and tablet using Gmail under Android 7. Some days are better than others but this problem is consistent for me on only one of the four email accounts and has been for years. I also went through the same old support routine of changing passwords and re-adding the email account to Outlook etc. The problem has been getting worse these last couple of days and today its occurring constantly. IMHO the problem seems to be on the COX server side. I bet my email account with the problem is not on the same server that our other three accounts are on. I will add that I also have two Gmail accounts that do not have or have ever had this problem. I gave up on trying to get Cox to fix this problem and am converting over the Gmail. I’m sure that Googles email customer service could be just as bad as Cox but if you don't have any problems you don't care. Thank you Cox for years of E-Mail frustration.