global email deliverability ratesEmail deliverability remains a problem, particularly in North America, where 20 percent of permission-based commercial email  landed in the junk folder or wasn’t delivered at all.

Things went slightly better last year in Europe where 3.6 percent of the same type of email was junked and another 11 percent went missing entirely. The Asia Pacific region performed marginally better.

These are more deliverability findings are the result of a ReturnPath survey that reviewed data from 131 ISPs in the U.S., Canada, Europe, and Asia-Pac from July through December of 2009.

A consistent issue in email deliverability is reaching business inboxes, as these tend to be guarded at the gateway by systems such as Postini, Symantec and MessageLabs. Only three-quarters of email makes it through these hurdles to the inbox, a very slight uptick from the 72.4 percent rate for the first half of 2009.

The survey also breaks out deliverability by ISP. BellSouth increased their non-delivered rate by 8 percent in the second half of 2009, as compared to the first half of the year. Yahoo was also up 3 percent to 18% in the second half of the year. In the UK, Demon and BT Internet, with 24.7 percent and 21.8 percent respectively, had the highest non-delivered rates.

ReturnPath cites a number of factors accounting for sub-optimal delivery, but most come down to a lack of best practices in light of the wide perception that email makes for easy ROI. Marketers aren’t cleaning bounced addresses out of lists, and are ignoring email basics such as welcome messages, functioning opt-out mechanisms and obtaining corporate permissions to send.