Return Path: 77 percent of delivery problems from sender reputation
A recent study from e-mail marketing firm Return Path showed that 77.3 percent of delivery problems were directly due to the sender's reputation.
The study measured 550 e-mail messages with poor delivery rates and found that when commercial e-mail does not get delivered to the inbox, the sender's reputation is mainly to blame, with the reputation of domains included in the e-mail responsible 6 percent of the time.
Return Path conducted this study with its Sender Score Resender tool that lets clients automatically test delivery failure root causes by resending the same message to test accounts via clean IP addresses. If the messages are delivered to the inbox on this second send, it shows that the originating IP's reputation, not message content, was the source of the delivery problem.
At Internet service providers where reputation was seen to be less important in e-mail blocking and filtering decisions, the common factor was the use of Brightmail. Brightmail filters in part on the reputation of the content, as determined by spam traps and complaints previously attributed to the content being mailed.
Receivers use factors such as e-mail volume, e-mail infrastructure (including authentication), unknown user rates, complaint rates, spam trap hits and listings on public blacklists and white lists when assessing a sender's reputation.