• March 21, 2005

Nearly one out of four--or 22 percent--of legitimate e-mails sent by first-time clients of e-mail performance management company Return Path were mistakenly blocked or delivered to spam folders last year, according to a Return Path study of 50,000 campaigns. Longer-term clients who used Return Path for at least three months had better results--their delivery rates were 9 percent.

The study found that the Internet service provider to block the most e-mail was RoadRunner, which tagged 36 percent of the opt-in e-mail messages as spam, followed by Mail.com at 34 percent, and Comcast at 31 percent. EarthLink blocked the lowest proportion of e-mail, at 5 percent, while BellSouth identified 6 percent of legitimate messages as spam, and CompuServe wrongly blocked 8 percent of messages. Per campaign, blocking rates ranged from 57 percent to 1 percent.

-- Wendy Davis