Before I became a marketing wonk I was a knowledgeable technologist, which is probably why I've never once enjoyed any e-mail system that I have used or implemented. Over the last 15 years, I have tried pretty much everything, from Pine to Zimbra, to MS Exchange to Lotus Notes and several different IMAP and POP options. Every time it's the same thing--the system works within reason but is never great. And there is always something that bites you in the rear.
I first started outsourcing e-mail to managed providers in 2003 when I worked for a CEO who demanded MS Exchange and we only had Linux boxes. It was never great and it was too expensive to boot. But the offerings have gotten much better and at this point I can't see a small- or medium-sized business running its own mail server. It's just not necessary.
Here are my fundamental hopes for e-mail:Reliable delivery of mail (dare to dream) Reliable delivery of mail on mobile devices (Blackberry and iPhone) Shared calendaring with administrator abilities (i.e. admin access) Backup and recovery Reliable SPAM prevention Sync across multiple computers and devices