Broadband customers with internet service provider Virgin Media suffered an email blackout this week.

The broadband supplier apologised after customers across the country were left with only intermittent access to emails between Monday August 24th and Thursday August 27th.

According to the company, it is not yet known what caused the outage but its engineers are looking into the matter.

"Virgin Media would like to apologise for any inconvenience caused," it said on the status web page for its cable broadband service.

"Full resolution details will be posted when available."

The issue was first identified on Monday morning, but took until 08.29 local time on Thursday to fully resolve.

Earlier this week, Virgin Media received a string of nominations for the upcoming Top 10 Broadband Awards 2009.

The internet service provider earned four nominations, including Best Broadband and TV Provider, Fastest Home Broadband, Best Wireless Broadband and Broadband Innovation award.

Rival broadband supplier O2 also secured four nominations.