I’ve recently been looking for a comprehensive list of mail/groupware servers/services that offer Exchange ActiveSync integration, e.g. for the iPhone or Windows Mobile. Since I couldn’t find one, I’m putting together a list myself. (I’m not including Microsoft Exchange Server and all those Hosted Exchange solutions, since they’re pretty obvioius choices.)
Kerio Connect‘s ActiveSync Support ($540 for 5 users)
Open-Xchange using OXtender for Business Mobility: ($21.75 / 14.50€ per user)
Scalix using Scalix ActiveSync: ($299 for 10 users)
Zimbra Collaboration Suite using Zimbra Mobile for Smartphones: ($25/$35 per user per year + $500/$1000 per year)
Z-Push (free, appears to with any IMAP server)
If you know any others, please go ahead and add them to the comments, and I’ll add them to this list.