How does Zimbra perpetual licensing work?

The Zimbra Perpetual license is a nontransferable right to use the license for the number of mailboxes in the agreement. At the end of the 1st year from the date of issuance of the Zimbra license key and provided that support is still generally available, customer can pay a maintenance fee to continue to receive support, upgrades and updates or can continue to use the then current version for the number of license mailboxes in perpetuity for no additional fees.