SMTP is a protocol used to SEND email. When you type an email and click "SEND", your mail client [Mail.app, Entourage, Firebird, etc] uses the SMTP protocol to send your email to your SMTP server (which may or may not be running Exchange), which then uses the SMTP protocol to send your email off to its final destination.
When you click "GET NEW EMAIL" on your mail client, the SMTP protocol is *NEVER* used to receive your email.
IMAP is one of the industry standard protocols for receiving email. If anything's pseudo, it's Microsoft's non-standard "MS-OXGLOS" protocol that they use to enable the features you seem to be talking about [calendars, contacts, tasks, etc].
As others have mentioned, to get a client that supports that, you need to get the more expensive version of Microsoft Office, or wait until the next version of OS X comes out (as the default mail client will support it).