The amount of spam crammed into UK inboxes has quadrupled over the past three months, according to figures from an anti-spam company.
The average internet user was targeted with more than 30,000 spam emails in the past three months, ClearMyMail claims.
Its spamming index said the worst hit were customers who had Orange as their ISP, where spam accounted for more than 96 percent of all emails received between April and June.
Dan Field, managing director of ClearMyMail, pointed to an increase in broadband availability in the UK as a primary cause for the increase, enabling phishing emails to be sent out in far greater numbers.
Field also identified the changing nature of spammers as a factor in the number and type of spam sent out. He said: "Spamming is now done by organised crime using local gangs who know how to target customers and how to make their spam look legitimate.
"The type of emails are now more dangerous. There are now more fraud emails rather than just spam offering you Viagra."
In response, Orange said: "Orange takes email spam very seriously. We are an active member of the Messaging Anti-abuse Working Group and deploy a mixture of proprietary and third-party anti-spam filtering software, which we provide free to all our customers.
"With any automatic filtering there is a danger of it identifying email that the customer actually wants to see. Therefore, we choose to tag the spam and deliver it to the inbox and make it a choice for the customer to turn on their anti-spam settings, via their webmail, to deliver the tagged email to the junk folder."
Of financial services companies, The Royal Bank of Scotland was the name most used by fraudsters sending email, with nearly half of all phishing emails pretending to come from the bank.
Field said: "It tends to go in cycles who they target with gangs tending to target the banks with most publicity. They will go for the biggest banks because there's so many more customers who are likely to click on an email."
But an RBS spokesperson said: "This research simply doesn't reflect our experience, it's an unreliable snapshot and RBS didn't even feature in their previous table for quarter one of this year.
"We have developed significant security processes to protect against this type of threat, including sending more than two million card-reader devices to our customers with the specific purpose of protecting them from online fraud such as phishing."
A fifth of UK spam is now generated within the UK, which, Field points out, is more difficult to identify as spam than emails generated from previous hotspots China and Russia.