A study of the number of instances permissioned commercial mails failing to reach the inbox of the recipients was studied by Return Path.  Here are some interesting statistics observed

Global Email Delivery Rates
North America
Inbox : 80.1%
Junk/Spam : 3.5%
Missing : 16.3%

Europe
Inbox : 85.5%
Junk/Spam : 3.6%
Missing : 11%

Asia Pacific
Inbox : 86.9%
Junk/Spam : 2.5%
Missing : 10.7%
* missing is not the same as bounced mails. These are mails that are not delivered without any notification to the sender about non-delivery

Email Non-Delivery Rate By ISP – H2 ’09
BellSouth : 21.5%
Gmail : 20.7%
MSN : 19.2%
Hotmail : 19.1%
Yahoo : 18.5%
AOL : 17.0%
Comcast : 14.7%
Road Runner : 14.6%
NetZero : 12.2%
USA.net : 11.2%
Cox : 5.5%

Keep yourself updated on all the technology news by following us on Twitter or by joining us on our Facebook Page.