A day after Yahoo's email service suffered a partial outage, the company reported that about 1 million users were affected.
The problem began at 7:30 a.m. Pacific time Thursday and was at its worst at 11 a.m., according to Stephanie Shum, senior product manager for Yahoo Mail. At the problem's peak, about 1 million users were without email service, she added.
"We have isolated the root causes of the problem and have restored service," Shum wrote in a blog post. "No email data was lost or at risk. We understand that being denied access to your email is extremely frustrating. We are taking steps to prevent this kind of outage in the future."
It's not clear when Yahoo got email back up for all of its users. Yahoo also did not specify what caused the problem.
While Yahoo email users have been tweeting about being happy the service is online, many say they resent the downtime -- even if they don't have to pay for the service.
"Yahoomail outage at such a critical time for me: I should have been faster with the gmail migration.. #OUCH," tweeted Saemon.
And ADVoPM tweeted, "The #yahoomail outage has seriously affected our ability to do our work today. Need to find a yahoo alternative."
Sharon Gaudin covers the Internet and Web 2.0, emerging technologies, and desktop and laptop chips for Computerworld. Follow Sharon on Twitter at @sgaudin or subscribe to Sharon's RSS feed . Her e-mail address is firstname.lastname@example.org.