Mail not working on Mini IPad

Hello, I have had 2 yahoo e-mail addresses on my Mini IPad Mail app for months now and since this week-end there is no sync anymore, I di not receive new mails nor can I download what was in the folders nor can I see sent e-mails.

I have tried to delete the accounts and start again but this did not help. My yahoo accounts on my Mac work perfectly, it is really a problem with the Mini Ipad. It sees the number of e-mails in each folder but does not download them at all nor updates the inboxes.

Just one of the 2 works sporadically, the other has not been working for days now.

I get the message "load more messages... 160 total, 0 unread" and then nothing happens or I also get "connection to the server failed".

Thank you for your help!