Microsoft Teams Essentials is a good starting point into the Microsoft Modern Workplace for small companies that are really sensible about costs and benefits.
The offer is available to companies up to 300 seats and is less costly than other existing offers

Teams Essentials does not include SharePoint Online or Exchange Online mailboxes.
That is why the integration with Gmail and other third-party mail systems is key to Teams Essentials the integration is available also with with on-premises mail systems)