Email messages marked with an icon indicating its authenticity are twice as likely, on average, to be opened than unmarked messages, according to research from email identification company Iconix, writes ClickZ. Emails from online auction companies, which are frequent targets of phishing attacks, benefited most, with the open rate increasing 404 percent.

Open rates least affected were for online retail emails (a 40 percent increase) and those regarding news/information services (a 26 percent increase).

Open rates increased significantly for e-cards (192 percent), travel services (189 percent), social networks (115 percent), and dating sites (107 percent); phishing-susceptible financial institutions' and online payment services' open rates increased 70 percent and 68 percent, respectively.