We are looking at using Zimbra to replace Exchange 2003. We have approximately 500 users, but only 50 use Outlook. The rest are either web access users or SMTP/POP3 users. Is there a way to combine the Net Ed and OSS to reduce the cost? It's very hard to justify $30,000 if only 10% of the user base needs Outlook functionality.

Also, if this is not the right forum for this question, can you point me right?