iPad mini Email problem on IPad

[BASRPH]

I have 2 yahoo accts on my IPad mini. Most of the time they work OK, but not always. For the last 10 or 12 hrs when I try to get email I receive the message " connection to the server failed". I have deleted each acct and re-installed them but the problem continues. Any suggestions??

 

[nightlong]

That only happens on my iPads and iPhone sometimes when they've been asleep for a while. I have to quit Mail, not just close it, and then reboot the app, then it connects.