oho mail on iPhone/iPad won't connect

oho mail on iPhone/iPad won't connect

For the life of me, I can't get my zoho email accounts to work on my iPhone 6 and iPad.
I have tried all the appropriate settings, ssl, ports, etc. with correct username and password with no luck.  It keeps saying that the user name and or password is incorrect.  I did not go through the 2 step authentication with Zoho so that should not be the issue.
Any suggestions?
Thanks,
Josh