At 5:21am AEDT on Thursday morning, the company placed a notice on its support site reading: "Customers may be unable to send or retrieve e-mail. We are working to fix the problem as quickly as possible and apologise for any inconvenience."
By 8:00am, the site was predicting that the problem would be fixed by 10:00am, but at that time the estimate was revised to 1:00pm -- almost eight hours after the problem was first acknowledged.
A BigPond spokesperson said that the problem was due to "some network issues" and referred further queries to Telstra's central office. A Telstra spokesperson said that a network failure early today had caused some congestion.
"We're still investigating the root cause; obviously the priority is to get customers back online," he said. The network failure had also affected some other ISPs, the spokesperson added.
While Telstra claims that its core e-mail applications were restored by 10am, its site continued to list 1:00pm as the estimated fix time, and some customers were continuing to experience problems with e-mail access. Some parts of its corporate site were also experiencing application problems.
With more than 1.5 million customers, Telstra is Australia's largest ISP. The company suffered an embarrassing and extended series of service and e-mail outages in late 2003, and spent millions of dollars trying to fix the problem.