"We know many of you are having trouble accessing Gmail right now -- we are too, and we feel your pain," read a post to the Gmail blog.
The outage occured shortly after 4 p.m. ET. By 5:15 p.m., Gmail was accessible -- although users had to enter letters in a box to ensure they were human, and not an automated machine. By 5:45 p.m., Gmail service appeared to be fully restored and operating as usual.
Google's Gmail service is used worldwide by millions and is one of the most popular e-mail servers in the world.