You say that identities should not be used to check different mail accounts. I don't understand, is there another way to do it or are you saying that Pegasus is not designed to use to check multiple email accounts.
Perhaps the language I used was misleading. Although you CAN use identities to check different accounts, for most people it is not necessary. Identities are a confusing concept and many people incorrectly think that they have to set up a new identity for each e-mail account that they want to check.
Any single identity can have many different mail accounts that it can send and receive through. Identities are designed to allow you to have different settings in the main Pegasus Options without logging in as a different user. For example, if I use Pegasus at work, I might have two mail accounts under my main identity - one for personal e-mail and one for work e-mail. However, when I send messages to people who contacted me on my personal account, I may want to have the sender address as something more friendly or even a nickname. Changing the identity used to send the message might allow me to have my name appear as "Big Bad Sharky" and also use a different outgoing server. Then I'd change back to my work identity where my real name is shown.
As I've said previously, you can add as many of your e-mail accounts as you wish to the "Check these POP3 hosts for mail" box in the internet options. Each identity can check a different list of accounts if that is what you need.
Does that all make sense?