Broadband provider Eclipse has revealed that it blocked over 503 million spam emails over the course of July.
The company used its anti-spam and anti-virus solution to successfully stop 98.2 per cent of all spam from reaching customers.
Suspicious emails are checked by Eclipse and automatically deleted before appearing in users' mailboxes.
"Spam email is a real nuisance and can pose a security threat to customers," said the firm's director of broadband operations Clodagh Murphy.
"Unsolicited email unfortunately is becoming more prolific as internet usage continues to increase. At Eclipse, we try to ease the pain for our customers with our very effective anti-virus/anti-spam solution."
Recent figures from ClearMyMail found that 31,000 spam emails were blocked by UK internet users during the second quarter of 2008.
More than 80 per cent of the emails received by Orange, BT and Tiscali subscribers were rated as spam in the survey.