I would like to try Zimbra, I am the official guinea pig at our company, but the available hosted offerings do not fit the bill, makes it hard to migrate from Exchange.
I found one hosting partner in the list that offers a single account with mobile sync, with a free trial. I signed up for the trial, but it apparently included all of the hosting company's other products except their re-branded Zimbra. Not a good way to start a product evaluation.
1. Hosted Zimbra that does not require MX changes or DNS juggling to simply check out the product. We forwarded individual pop3 mail, on a case by case basis, to our current hosted Exchange server for 4 months before we made the mx changes. We tested and started migration on the host's subdomain, and made the mx changes when we were ready for 100% commitment.
2. Hosted Zimbra that allows a single account, rather than a minimum of 3 to 5.
Zimbra demos look great, hopefully I missed a hosted option that will let us see if we want to get into the game.