Trouble with Cached Exchange Mode in Outlook

Yes, I know we're a little behind. We have not yet migrated to Office 2007 or Exchange Server 2007. Even though we are a small business with only about 100 seats that's still a big financial commitment. Maybe we'll take the plunge next year. But for today, we are still running a very reliable Exchange Server 2003 Enterprise Edition with SP2. Other than needing to occasionally add storage space, it has been working just fine in our organization for the last three years. Management likes that and so do I.

One thing that management doesn't like is Cached Exchange Mode in Outlook 2003. I don't know why it's so much trouble for them. It works fine for me - always has. We may have a scenario that taxes the capabilities of Cached Exchange Mode to the max. In case you don't know, Cached Exchange Mode is simply Microsoft speak for Offline Folders - a local cache of what's in your mailbox on the Exchange Server. We only use it for employees in remote offices or home offices of execs.

Here is the scenario: Executive A is a high-volume, high-density email user in a far city. He easily sends and receives several hundred emails each day, most of them with large attachments of photos or PDFs with embedded photos. We're talking 5 to 10MB of attachments on many of his daily emails. I have never figured out why it has become so acceptable to send such large attachments. It just kind of evolved over the past few years.

Our industry happens to be aircraft sales but the same scenario could exist in Real Estate, automobiles, yachts or any business that needs to send lots of photos back and forth. The executive in question also uses multiple computers - one in the office and one in the home office, both on the East Coast of the U.S. Both his computers are configured to get his email from our Exchange Server on the West Coast of the U.S. using Outlook 2003 and Cached Exchange Mode.

The executive will work all day on the office computer, log off and then work all evening on the home office computer. The complaint is that it will sometimes take hours for synchronization of the offline folders to take place when first firing up one or the other to check his email. He reports that some emails are delayed by many hours while the cache is playing catch up. His mailbox size is over 7GB with over 32,000 individual email messages in multiple folders.

The far city does not have an Exchange Server. We only have the one on the West Coast. All email flows here and then out to the remote office. The remote office is connected via a VPN - a full T1 line here and a 3.1Mbs / 768Kbs DSL line there. The connection speed on the remote home office is a modest 1.5Mbs / 384Kbs DSL with no VPN. Most of the trouble seems to be when connected at the remote home office. Outlook is configured to get email via RPC over HTTP.

I know this reads like an MCSE exam question. Besides cutting his mailbox size down to a more manageable size, what would you recommend?

Update: I posted this same entry on my Tech Republic blog and received many good suggestions and recommendations there. That's why I post most of my stuff on Tech Republic these days. It has a much larger readership of tech guys like me.