Google Inc. on Tuesday apologized for an outage of its Gamil service, which leaves millions of people worldwide without e-mail for several hours.
"We know how important Gmail is to our users, so we take issues like this very seriously, and we apologize for the inconvenience," Google said in a posting on its website.
Gmail became what was referred to in online chat forums as "Gfail" at approximately 0930 GMT and remained inoperative for two-and-a-half hours.
Gmail service was reportedly disrupted for an estimated 113 million users in Europe, Asia, the United States and elsewhere.
Tuesday evening, Google posted an explanation of the problem on its blog. It appeared to be the digital equivalent of the rolling lackouts that happen when some minor glitz at a power plant short circuits the power grid for half the country.
In this case, Google shut down one data center for a software update, which overburdened other data centers that were supposed to cover for it.
Gmail service crashed a couple of times last year but had operated uninterrupted since it was bolstered with features that include people being able to draft and read messages offline.
To make amends for the glitch on Tuesday, Google is giving 15 days of free service to businesses, government agencies and other subscribers who pay for an expanded version of the product.