Microsoft on Wednesday released a standalone Outlook for Mac Preview version for free, as part of an attempt to gain more feedback on Google account upgrades including Calendar and Contacts integration.

The code represents the "earliest Outlook for Mac Preview build," Microsoft said, and is aimed only at people without an Office 365 subscription. Those who do have a subscription need to join Office Insider Fast to receive the same material.

Indeed, Insider Fast users have had access to extended Google support since early March. Microsoft cautions that the program supplies potentially risky builds that are on the cutting edge of Office development.

Google Calendar and Contacts data should sync like everything else in Outlook, with similar editing options. Microsoft is also building in a better Google setup experience, plus enhanced Gmail support, including Focused Inbox compatibility and automatic detection of travel and package information. The latter features were previously restricted to people with an Exchange, Office 365, or Outlook.com address.