Google's Gmail e-mail service is currently down for a majority of its tens of millions of users, the company acknowledged Tuesday afternoon.

"We're aware of a problem with Google Mail affecting a majority of users. The affected users are unable to access Google Mail," reads an alert posted at 3:53 p.m. U.S. Eastern Time in the Google Apps Status Dashboard.

In that dashboard, Google offers performance and availability information about the online services included in its Apps collaboration and communication suite, such as Gmail, Calendar, Talk, Docs and Sites.

In the alert, Google said it expects to offer an update on the outage at close to 5 p.m.

Gmail is one of the most popular webmail services in the world, not only among individuals for personal use but also as a component of Apps, which is designed for use by organizations of all sizes and educational institutions.

As such, Gmail outages are immediately felt worldwide, especially among people and companies where it used for business communications.