In their effort to protect users from spam, ISPs and hosted email providers inadvertently block and filter legitimate e-mail messages. A report published this week by Lyris Technologies measured deliverability rates for legitimate opt-in email marketing messages among over 30 major ISPs.? In the U.S., CompuServe and SpamCop dominated the field each of which delivered around 97 percent of the requested email to their customers? in-box without mislabeling it as spam.?
Overall, the study found that Internet and email service providers are currently operating at an average gross deliverability rate of 92.5 percent for opt-in email marketing messages, while the average rate of inbox deliverability is somewhat lower at 88.5 percent.