Gmail is a free, advertising-supported email service offered as part of Google's G Suite, with 15GB of storage, color-coded inbox filters and unsend button.
Zendesk is a cloud-based customer service software solution trusted by over 40,000 organizations worldwide. Companies such as Groupon, Box, and Zappos are using Zendesk to lower costs, raise productivity, and increase customer satisfaction.
Microsoft Office is a suite of desktop productivity applications and client and server software designed for data analysis, presentations and numeric manipulations.