A fire at a communications center has been blamed for crippling email services for millions of au brand mobile phone users since Sunday.
KDDI Corp. and fire authorities confirmed the fire, which damaged equipment at the center, in Tochigi Prefecture, also caused its email servers to shut down when the air conditioning failed due to high temperatures from the blaze.
Emails began being disrupted around 6:30 p.m. Sunday.
The disruption was affecting almost 8 million users at one point. As of 7:30 a.m. Monday, about 1.6 million users were still being affected, according to the company.
KDDI suffered a similar service disruption in February 2012, affecting as many as 6.15 million subscribers. The company attributed the incident to a failed power unit at the same communications facility.
A series of service disruptions that afflicted KDDI between the end of 2012 and May 2013 prompted regulators to issue administrative guidance to the mobile phone operator.