Millions of Gmail users were unable to get to their messages for about an hour on Tuesday due to a disruption at Google's free Web-based email service.
The problem affected about two percent of the approximately 350 million Gmail users, according to updates posted at a Google dashboard monitoring the status of its online applications.
"The problem with Google Mail should be resolved," the most recent message at the dashboard said.
"We apologize for the inconvenience and thank you for your patience and continued support," it continued.
"Please rest assured that system reliability is a top priority at Google."
Explore further: Survey: Harassment a common part of online life