Cannot reinstall my Apple mail account

Hi. I deleted this account on my iPhone because I kept getting the error message connection to server failed, but I cannot reinstate it. I enter my username and my password, no problem, and all looks fine. Then I get the screen with the list of providers and the option of adding an account. No account has been added

i did the same with my iPad and reinstalled the account without any problems

i should add, however, that on iPad I still get the same error message so reinstalling it did not work

• so my question is a two parter. How to reinstall the mail account on my iPhone and how to get rid of error message