Email security vendor MailFrontier is warning that the number of spam and phishing messages could top 1bn this Christmas.

Last year 750m mails were sent over the Christmas period, with both bogus sales offers and phishing attacks. The company is also warning of new kinds of social engineering attacks that consumers may be susceptible to.

"The festive season represents a great opportunity for cynical fraudsters wishing to exploit novice online shoppers," said Vanessa Wade, general manager of EMEA for MailFrontier.

"Traditionally, we see a massive jump in spam and phishing in the weeks leading up to Christmas and a number of new tricks emerge."

One new method is to send a fake invoice via email and ask the recipient to confirm or cancel the order. In order to cancel the order users have to input their credit card details so that their account can be credited.

People are still very poor at spotting phishing emails, according to a phishing quiz hosted by the company. Of the 500,000 people who have taken the test, just four per cent correctly identified all the phishing emails, and on average visitors fell for 25 per cent of phishing attacks.