Yahoo services have been down for several hours with thousands of its email users becoming furious over having no information on how long the outage will last.
"You may not be able to access some of our services, including email. Our top priority right now is getting this fixed. We appreciate your patience", Yahoo Customer Care said in a statement.
BT Yahoo email users have taken to social media platforms to complain about the outage.
According to the latest information, the reports of problems began just after 6 a.m. GMT.
The Downdetector.com website shows that users in Europe have suffered most from the outage.