More than 20 percent of commercial, permission-based email does not reach the inboxes of intended subscribers in the United States and Canada, according to email management firm Return Path.
The study found emails reached only 79.3 percent of inboxes in the United States and in Canada during the first half of 2009. With the undelivered email, 3.3 percent is routed to a junk or bulk email folder and 17.4 percent is not delivered at all.
"Many marketers aren't even aware that one-fifth of their emails are never reaching the inbox," said George Bilbrey, President, co-founder, Return Path. "In many cases, marketers are seeing 'delivered' metrics that repeatedly show a 95% to 98% delivery rate. Unfortunately, many ESPs and marketers have developed the belief that whatever emails aren't bouncing have successfully reached the inbox."
"That's just not true, as these numbers show. Marketers need to examine their current deliverability stats, and remember that hard bounces aren't the only emails that aren't reaching your subscribers."
The U.S. deliverability rates are slightly better than Canada with an average of 82 percent reaching their destination, while Canada's inbox rates are lower with 75 percent of emails landing in subscriber's inboxes.
Successful deliverability to subscriber's inboxes varies by ISP. The top five U.S. ISPs ranked in order of difficulty for marketer's emails to reach user's inboxes are Gmail, Hotmail, MSN, Comcast, and AOL.
Marketers have an even more difficult time reaching business email addresses that are protected by email monitoring systems such as Postini, Symantec and MessageLabs. On average, 27.6 percent of commercial emails sent to business addresses don't reach the inbox.
"As ISPs continue their daily battle to keep consumers' inboxes protected from the onslaught of spam, legitimate commercial emails that consumer want to receive aren't being delivered," said Bilbrey.
"It's imperative that marketers dig into their deliverability stats to truly see how many of their emails are successfully reaching the inbox."