You need, first, to establish whether the email account supports POP or IMAP. You'll need at least one of these account types to set up any email program.
Next, you will need:
The name of your incoming mail server. This may look something like mail.yourserver.com or pop.yourserver.com.
The name of your outgoing mail server. This may be the same as the incoming server, or may look like smtp.yourserver.com.
Whether either the incoming or outgoing servers need any specific port numbers, whether outgoing mail needs authentication, and whether either needs SSL (a secure protocol).
Once you have this information, you can plug it into Mail, or post back and let us know, and we can help out.
Matt