The combined average gross deliverability rate for permission-based e-mails increased from 87% in the third quarter of last year to 89% in the fourth quarter, according to a recent study by Lyris Technologies.
The study also found that users with addresses with one of the top 10 U.S. providers were appreciably more likely to receive their opt-in e-mail (97.5%) than those who used one of the bottom 10 providers (76.4%).
The only note of concern in the report was an increase in false-positive spam filtering by Yahoo! domains in Europe. Yahoo! was the sole European Union provider, however, to see an increase in legitimate e-mails being filtered as spam. This increase caused the average for all false-positive spam filtering to increase from 1.2% to 2.6% in fourth quarter of 2005.
Earthlink joined the ranks of the top 10 domains by dramatically improving deliverability in fourth quarter by 5%, becoming the second-best ISP for gross and inbox deliverability. Knowlogy and Mac.com also joined the top 10-delivering ISPs, improving deliverability by 3% and 2% respectively.
False-positive filtering by CNC.net remains high but decreased 24% over 2005. Gmail has also reduced false-positive filtering 15% from the first quarter of 2005. Hotmail’s false-positive filtering has nearly tripled, from 5.3% in the first quarter to 15.7% in the fourth quarter.
The Lyris E-mailAdvisor service monitored the full delivery trajectories of 60,928 production-level, permission-based e-mail marketing messages (nondiscussion) sent from 49 businesses and nonprofit organizations to multiple accounts at 40 ISP and ESP domains in the U.S. and Europe between Oct. 1 and Dec. 31, 2005. In all cases, the recipient addresses to which the publications were sent had made an explicit opt-in request to receive the messages.