Hello,

We are really sorry for the inconvenience.

Please follow steps below to change settings on Ipad :

Go to Settings > Mail > Account and select forget this account. Then with your account information, from

Settings > Mail > Add Account and re-enter all the account information manually. Make sure you set the Incoming protocol to POP if that is what you have. Enter all of the server names for the incoming and outgoing servers, passwords, etc. Then go to Settings > Mail> Account and under Advanced set the delete from server to the time period you want, or never.

If the issue is still not resolved please contact Apple customer support to get help on the issue.

Thanks

Jason