"We also count issues for any number of impacted users, not just if 'enough' users are impacted," he said via e-mail.

The competition between Google Apps and BPOS has been heating up in the past year. Google has been updating its suite with capabilities aimed at large enterprises and their CIOs. Google Apps has traditionally been aimed at small and medium-size businesses.

Meanwhile, Microsoft is beta testing a big upgrade to BPOS called Office 365, whose applications will be based on the latest 2010 versions of their on-premise counterparts. Office 365 will also include versions that come with Office Web Apps, a hosted version of Microsoft Office, and with the option of the full-featured Office suite itself.

Because BPOS and Google Apps are cloud-hosted suites, their performance and uptime are critical aspects to their respective customers, most of whom rely on the suites as their primary workplace e-mail service.