Setting up your email inbox on an iPhone is a relatively easy task. Simply go to Settings and then Mail, Contacts, Calendars. After you choose the option to Add New Email account, fill in the needed details on the first step. Now, when selecting the IMAP or POP3 tab, you will be asked for hostname, username, and password. The hostname in the case of IMAP is imap.yourdomain.com, and the one for outgoing server is smtp.yourdomain.com. (replace yourdomain.com with your actual domain name).