Outlook 2016 continually prompts for username and password constantly and will not sync

I am using Outlook 2013 and email on my android device. Yesterday I received an email from Cox saying welcome to your new email, cox email is all new. Today I am getting the enter server password screen every 5 minutes on both outlook and android. I chatted with tech support and their final answer after asking me to " turn it off and on" again was we don't support Outlook or other 3rd party products. Thank you Cox for my new email service. 

This started happening to me (and others in family) a couple days ago.  On an iPhone or iPad the message is "Cannot Get Mail.  The user name or password for "Cox" is incorrect. OK or Settings"

On Outlook 2016 it's "enter your user name and password for the following server".  Server is pop.cox.net and settings are just like Cox has in their email user guide.  I just ignore the message or enter OK and then a couple minutes later it usually works, until later that day or next day.

http://www.cox.com/residential/support/internet/article.cox?articleId=a8fb24c0-6440-11df-ccef-000000000000 

There are similar guides for iPhone and iPad.

P.S.  It is NOT a new problem.  

If by "new enhanced features" you mean email accounts that were previously working that stop working, tech support that is clueless about the problems and blames everything on Outlook, password problems, the moon phase, etc.

Then yes, I have been enjoying the "new enhanced features" since April 27th.  I just don't have reliable email.

I've been seeing the same issue on Outlook 2010 and 2016 for some months.  It seems to have gotten worse lately.  I've changed passwords, based on the original suggestions.  I only seem to see the problem on the Cox account, one of 3 that I use regularly.  Is there anything to the speculation about timeout settings on the Cox servers being part of the problem.  I've seen the problem on multiple computers.  I don't see it on iPhone, iPad.  I don't use webmail frequently; so, I'm not sure if it occurrs or not.  The problem is very annoying.

Mine is still occurring.  I can't check my mail without the *** thing popping up.  Unbelievable that this issue is this old, tons of people having the issue  yet Cox just shrugs their shoulders and says "wait until we migrate you"..

I'm using Thunderbird and have the same exact issue.  I've tried everything.  It seems to work for a short while then I get the errors again - wanting me to put in my password and sending is failed.  I was getting it only on outgoing emails and recently a couple of friends said emails to me were getting bounced back to them un-deliverable.  Three different phone calls with Cox and they can't fix the problem - keep telling me they have to bump it up to a higher level.

Frustrating!  This is why I strongly dislike Cox - along with their "package" deals.

This is not a temporary problem!  Look at everybody's comments.  Been happening for a while and not just one or two days!

Now not only am I having the same problem as everyone else is posting about email wanting a password continually, some of my friends are saying emails they are sending to me are getting bounced back with this error -  

UNBELIEVABLE!!

This is the mail system at host mx.cox.rs.oxcs.net.

I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can delete your own text from the attached returned message.

                   The mail system

<nikang3@cox.net>: delivery temporarily suspended: host
    mx.east.cox.net[68.1.17.3] refused to talk to me: 554 eastrmimpi110.cox.net
    cox 146.20.112.69 rejected - no rDNS - Refer to Error Codes section at
    http://postmaster.cox.net/confluence/display/postmaster/Error+Codes for
    more information.

The comments from people using Outlook and Cox responding that it's an Outlook problem is utterly ridiculous!  I have Thunderbird and am having the exact same issues!!