Can I get Zimbra if I want fewer than 25 mailboxes?

Zimbra licencing is in multiples of 25 mailboxes, so there is one option if you want less than 25:

You can subscribe to a ‘Hosted Service’. This is often referred to as The Zimbra Cloud. Specialist Zimbra Partners, called Business Service Providers (BSP) operate multi-tenancy Zimbra servers, hosting email services in a secure environment. They will provide the exact number of mailboxes you need without the need to manage your own installation. This service offers you the opportunity to provision and delete mailboxes as you wish, with monthly billing and no long term commitments.

Contact us for more information.