Postbox makes it easy to add new mail accounts via the new mail account wizard which can automatically detect your mail server settings for you.

Open The New Account Wizard

Select Preferences... from the Postbox menu. (For Windows users, do Tools | Options...) and then select the Accounts pane. On the lower left, click on the Add or + button and choose Add Mail Account...

Enter your full name (as shown to others), your email address and the password associated with the account.

Automatic Setup

After entering your name and e-mail address, select Continue. Postbox will attempt to automatically configure the correct settings for your mail and SMTP server for the new account. In most cases, afte this step, you are done! If your account settings cannot be determined automatically, or if you would like to override the default settings, click the Edit Settings button and enter your settings.

Manual Setup

If you prefer to manually enter your server settings, click the Manual Setup.... This will allow you to customize your account as POP3 over IMAP and specify the settings manually.