To add an account to the Mail app on an iPhone/iPad, follow the steps below:
Incoming mail server:
Host Name: servername.host-serve.net (replace servername with the hostname of your server)
Username: <your full email address>
Password: <the password you set for the account>
Outgoing mail server:
Host Name: servername.host-serve.net (replace servername with the hostname of your server)
Username: <your full email address>
Password: <the password you set for the account>
If a message appears saying "Cannot Connect Using SSL", choose "No" and then cancel/exit the account setup process and follow the steps above again from step 1.