Programmatically use Gmail to receive e-mail?

Question

I'd like to use a C# program to poll a gmail account and automatically download new messages. I know you can use gmail as an outbound SMTP server, but is there any way to access new messages sent to the account?

EDIT: Thanks for the rapid feedback....so I have two options, POP or IMAP.

Which one should I use? And why?

EDIT #2: Looks like IMAP allows me to not have to poll. Looks like the way to go.

Answer 1

Use Gmail with IMAP.

Answer 2

You can configure GMail to let you get at your mail with a POP3 client.

Answer 3

You can get an Atom Feed of your GMAIL, which can be fetched with a regular web request, and parse as a regular XML document. I made a PHP page I could access from my phone (which doesn't support Atom Feeds, or pages as advanced as Google Mobile), to show me a list of new emails.