iPad- Cannot send emails

for the past few weeks I have been unable to send any emails from my cox email on my iPad. I do not have this problem on my iPhone. I have rechecked all server and port setting per the Cox instructions, as well as my password on the smtp server settings. I have deleted and recreated the account, all the steps purported by cox tech support to “solve” the problem. None of it works. I have other email accounts and only my cox email has this problem.