How to obtain an Exchange Hybrid Edition product key for your on-premises Exchange 2007 or Exchange 2003 organization.
If your on-premises Exchange organization is running Exchange 2007 or Exchange 2003, and if you want to connect your organization to Office 365 and your Exchange Online organization, you must install at least one on-premises Exchange 2013 or Exchange 2010 Service Pack 3 (SP3) server. This server is used for hybrid deployment connectivity that seamlessly connects your on-premises Exchange and Exchange Online organizations. To avoid the additional cost of an Exchange 2013 or Exchange 2010 SP3 server license, you may qualify for a free Hybrid Edition product key for Exchange 2013 or Exchange 2010 SP3.
Obtain a Hybrid Edition product keyYou can request a Hybrid Edition product key if all the following conditions apply to you:
- You have an existing, non-trial, Office 365 Enterprise subscription
- You currently do not have a licensed Exchange 2013 or Exchange 2010 SP3 server in your on-premises organization.
- You will not host any on-premises mailboxes on the Exchange 2013 or Exchange 2010 SP3 server on which you apply the Hybrid Edition product key.
References:Need help to set up your hybrid deployment? Access a customized, step-by-step hybrid deployment configuration checklist at the Exchange Server Deployment Assistant