Let me ask the dumb questions right off the bat:
1. Did something change recently (new service pack installed, got moved to a
different email server, had to reinstall a driver, anything) that coincides
with the slowdown?
2. Have you installed the service pack for Office 2007?
3. How is your email configured? POP, IMAP, Exchange, cached mode (OST),
etc...

Signature
Thanks,
John Guin
OneNote Test Team
http://blogs.msdn.com/johnguin
> Until very recently, clicking the Calendar button in Outlook would open my
> calendar immediately. Now, clicking it results in a lag of as much as 30
> seconds before the calendar appears. I share my calendar by publishing it
> online. I am running Windows Vista and Office 2007.