Four out of five e-mail messages in the fourth quarter of 2005 were either blocked or tagged as spam, according to the Messaging Anti-Abuse Working Group.

Moreover, the average e-mail inbox was the target of an average of 1,000 blocked or tagged messages during the quarter, according to MAAWG.

The group is the largest global trade association aimed at fighting spam, viruses and so-called denial-of-service attacks—or onslaughts of useless traffic designed to bring networks to their knees.

Its board includes AOL, Bell Canada, Comcast, EarthLink, Verizon, Microsoft and Yahoo and among others.

MAAWG’s spam report is the result of monitoring 100 million e-mail boxes, the group said in a statement.