Why has my mac email stopped working?

Blackberry Z30. two happy years with this lovely phone, have been devoted for a very long time. Suddenly I get an error blue-banded message saying mac is not responding, please check settings. Nothing worked each time i entered the age old mac information. So I deleted the account, and have tried to set it up again. No luck. At the 'saving and verifying your settings' it thinks for a while and then I get the 'at this time it is not possible to blah blah blah.. please try later. This has been happening now for several days. I've looked online for possible problems like this but can't find anything. I do believe I am entering the right settings, before you ask (quite rightly). AND I've restarted the phone both on a restart AND full power down and power up. Anybody have some brilliant idea, please? Thanks

Check your mac email account on line, go to their help site, as they may have changed incoming and outgoing port #'s?