Exchange over slow links?

A little insight into the networking between our office and the home office. We have a T1 to the internet. They have a T1 to the internet (for 50 people, but that's not really what this is about). We have a freeswan box on this end, they have a freeswan box on their end. IPSEC between the two.

The home office runs the gambit of Microsoft servers with no local replication of any of them. During the day, their T1 gets very saturated. Almost to the point of unusability.

For our email, we connect to the Exchange server out there--not necessarily a bad thing, but it is in this case. The problem arises when someone decides to email a largeish (in this case >500K) attachment.

Microsoft, in their infinate wisdom, has designed the Outlook/Exchange connection to be pretty tight where Outlook relys on the Exchange server for most everything. This hurts with large emails. When you click on the email to bring it up in the preview pane, it has to download the entire message and attachment. When you want to view the attachment, it has to redownload the attachment. If you accidentally click onto another message, you have to wait all over again.

Why can't they cache this stuff locally, and ask the exchange server if it has changed? MS has done some wonderful things with file transferring and caching with their BITS client, but I think that with road warriors and remote offices, they should look at optimizing some of their business applications.

Maybe I'll start using Outlook Web Access instead.