I get asked this so many times, I though I would save myself a bit of time, and publish a simple guide to setting up an iPhone for a POP3 or IMAP email account. Although the title says for cPanel, this guide is fine for just about any POP3 or IMAP account where you know the server and account details.
The screenshots were taken from my iPhone 4 runnng iOS 4.3.x. So, lets start.
Tap the Settings icon on your iPhone’s home screen. This will bring you to this screen (below).

Tap the Mail, Contacts, Calendars icon tp get the following screen.

OK, now tap the Add Account… icon to get the following screen

Tap Other

You guessed, tap the Add Mail Account icon (not too hard, is it?)

The New Account screen takes the basic details of your account:
- Name – This is the friendly name that will identify your outgoing emails (e.g. Steve Sant).
- Address – this should be your full email address for the POP3 or IMAP account.
- Password – This is the password that was configured for the mailbox (NOT your cPanel password).
- Description – this is just to help you identify the account in your settings later – call it anything you like.
Then tap Next at the top of the screen, which will bring you to the following screen.

Choose whether you want to connect using POP3 (messages downloaded locally to your iPhone) or IMAP (messages are kept on the server so you can also read them from your home PC/Mac). Just remember if you are using IMAP that you will start using up your user account space quota.
You will need to fill in the following:
Incoming Mail Server
- Host Name – This is almost always mail.domain.com – so if your email address is tommy@finger.co.uk, then your mail server is almost certainly mail.finger.co.uk
- User Name – For cPanel accounts, the account username is always the same as the mailbox address – if you are not using cPanel then you might have a different user name, but it will still be provided to you when you create your mailbox.
- Password – This should already be filled in for you, but if not, then enter your mailbox password again here.
Outgoing Mail Server
- Host Name – Again, this is almost always mail.domain.com, the same as your incoming server.
- User Name – Use the same details as you entered for your incoming mail server, above.
- Password – This should already be filled in for you, but if not, then enter your mailbox password again here.
Tap the Next button, at the top to verify your settings.
At this stage, you may get one or two responses from your iPhone:
1.) The SSL Certificate on the mail server you are trying to connect to, doesn’t protect the server name you specified
It is very likely that at this stage you will receive a Cannot Verify Server Identity warning. This is because the SSL certificate that is protecting your mail server is probably assigned to the main server name, and not your individual domain. If you contact your hosting provider, they should be able to tell you the right server names to use, to avoid this error.

You have two choices here. Continue, and ignore the message, or press Cancel and swith to using a NON SSL connection.
In all respects, it’s probably better to press Continue and ignore the problem. Although, strictly speaking, means that if you accidentally connected to another server (unlikely) or if you were the victim of DNS poisoning you wouldn’t know about it, it’s still a more secure choice than going with a NON SSL connection (which is still just as vulnerable to DNS poisoning).
2.) Your iPhone Cannot Connect Using SSL

This simply means that your mail server doesn’t offer the facility to connect using SSL. To be honest, if you get this, then there is something amis with your hosting provider’s server or, infinitely more likely, you have entered the wrong details somewhere. So tap No and go over everything again!
If everything worked out (and in most cases it should), then great! If you still can’t connect to your outgoing server, then read on…
Still got problems?
Advanced Incoming Mail Server Settings
If you need to alter advanced settings for your incoming server, then tap the Advanced button at the bottom of the account settings screen :

This will give you the following screen :

Here you can choose if you want SSL, the type of authentication, and when messages should be deleted from the server, if ever. You can also choose to use a non-standard TCP Port.
Advanced Outgoing Mail Server Settings
If you need to alter advanced settings for your incoming server, then tap the SMTP button at the bottom of the account settings screen :

This brings you to this screen :

You should see your chosen server at the top (as your Primary Server). All of the other servers should say Off (unless you are an expert, in which case you shouldn’t be reading this guide!). Tap on your Primary Server at the top, to bring you to the following screen :

Here you can configure the Host Name, User Name, Password, Use SSL, Authentication method, and TCP Port.
Many large ISPs block you from using SMTP servers outside of their network. You may run up against this problem if your iPhone connects to your home WiFi network and your home broadband is with one of the big providers in the UK or USA.
This is usually circumvented by connecting to your mail server using a different Port other than 25 (the default). For example, ziphost.co.uk use Port 525 as well as 25, so just change your Server Port to 525 and you you should get round the problem.

Great post,
Followed the instructions and got my pop3 working as a IMAP on my iPhone and iPad