FYI: Microsoft Exchange Server 2007 & end of support next year…
Yes you heard it right, Microsoft Exchange Server 2007 is approaching the end of support by next year; you can refer the Support lifecycle for it.
Customers who are using Exchange Server 2007 for any of their email and calendar services should begin planning to move the associated mailbox data and resources to Office 365 or update their infrastructure to a newer version of Exchange, such as Exchange Server 2016. If you’re using Exchange Server 2007 then you may want to use this opportunity to migrate your email/calendar infrastructure to Office 365 can take advantage of Microsoft FastTrack as well.
For more info you can refer: http://blogs.technet.com/b/exchange/archive/2016/04/11/exchange-server-2007-t-1-year-and-counting.aspx