We offer an email auto-config tool and instructions can be found here, however if you are required to manually add/edit your email settings, these are the instructions:
NOTE: In this example, replace 'yourdomain.com' with your own domain name without the 'www'.
1. From your iPhone main view, click on Settings.
2. Select Mail from the Settings menu.
3. Select Add Account from the Mail menu.
4. Select Other.
5. Select IMAP. Enter your name in the Name field, your full email address (firstname.lastname@example.org) in the Address field and a description for the account in the Description field. Scroll down and input the settings for your Incoming Mail Server. Enter mail.yourdomain.com in the Host Name field.
Enter your full email address in the User Name field and your password in the Password field.
6. Scroll down and input the settings for the Outgoing Mail Server (SMTP).
Enter mail.yourdomain.com in the Host Name field and replacing yourdomain.com with your own domain name. Enter your full email address in the User Name field and your password in the Password field.
Now click the Save button in the top right hand side of the screen.
7. Mail will then check your mail settings. It will verify your settings and add the email account.
Now when you press Mail, it will take you to your mail account.
8. Select Settings again from your iPhone, and then click on Mail.
9. Select the email account that you have just created.
10. Select the Advanced button.
11. Make sure Use SSL is turned OFF in both Outgoing Settings and Incoming Settings.
The port for IMAP should be 143.
Your set-up is now complete!
NOTE: If you run into any problems after setup, the easiest thing to do is to delete the account and setup the account fresh.