Hosted
Exchange: Miscellaneous Challenges. Apart from scalability, what are the most
pressing development issues that service providers should consider for the
hosted version of Microsoft Exchange?
In no particular
order, we suggest:
- There's
no integration with billing and provisioning systems. So you end up building
your own system instead of using a shrink-wrapped package.
- It's
complicated to understand and requires a lot of administrator training.
- It takes
lots of time and is expensive to administer. For systems with over 10,000
users, we estimate an average of five support staff, plus one support person
per additional 5,000 to 10,000 mailboxes. For 1 million users, that's 100
to 200 people.
- Service
providers have 24/7 operations, and it's hard to do backups online. Exchange
2007 has improvements in this regard, but still uses a monolithic database
file as the message store. This file grows very large and needs special third-party
tools (e.g., from Veritas and Computer Associates) to do backup. This adds
additional cost and complexity.
- Exchange
consumes a lot of resources. So you need pricey high-end 64-bit machines as
servers, costing around $10,000 instead of $2,000.
- It's
generally a challenge to deliver 99.999% uptime with Exchange.
- Small
businesses want to be able to have their own domains (e.g., they want their
own right-hand-side of the @ sign in email addresses). Exchange wasn't designed
for multi-tenant operations, and implementing this is hard to do with E2007.
... David
Ferris, with thanks to Rockliffe's John Davies