Yes you can. Any computer that is connected to the internet (not necissarily through xyz) or web-based email service, can ask our mail server for your mail. You simply need to provide the email software you have access to with the following information.

Incoming Mail Server (POP):	mail.xyz.net
Outgoing Mail Server (SMTP):	[whatever is appropriate for the system you're using]
Account:	[your username here] (the part before the @ symbol in your email address) (Eudora and some Macs require the form [username]@mail.xyz.net)
Password:	[your password here] (the same password you use to dial into xyz)
Reply Address:	[your email address here]

With this information, from where ever you are checking your mail, the email software you are using knows:
What server on the Net to ask for your mail (Mail Server).
Who's email to check on that server (Account).
Verify that you are who you say you are (Password).
And if you reply to mail your received, let the recipient know where they can send a reply (Reply Address).