Several PF officers have asked about setting up PF email on an iPhone. The process for other devices should be similar.
There is a set of instructions from Apple on their website.
Go to How to set up your email account manually on that page.
Go to Settings > Mail, then tap Accounts.
Tap Add Account as in screenshot below.
Tap Add Mail Account
Enter your name, email address, password and a description for your account
(the description is what it will appear as in the list of accounts on your phone)
Apple will not be able to detect your settings automatically, so the following screen will appear:
Select IMAP – this is important;
Note you will have to enter your email address and password three times.
At this point your phone should verify and set up your account successfully.