Lyris has released Q3 2005 ISP Deliverability Report Card, reporting that the combined average rate of gross email deliverability of permission-based email marketing messages for U.S. and European ISPs and ESPs fell slightly this quarter from a Q2 rate of 90 percent to a rate of 85 percent in Q3.

Inbox deliverability fell due to a rise in amount of blocked and undelivered messages among European providers, resulting in an average of 86 percent overall in Q3. U.S. providers enjoyed improved delivery of opt-in email in the same period, raiding b a full 4 percent to 89 percent.

Lyris also reported the result of monitoring 28 of U.S. domains. Concentric ranked the first and Gmail second for overall rate of false positive filtering at 42.47 and 7.17 respectively. Gmail ranked second for delivery of opt-in email messages though.

Download: Lyris Deliverability Report for Q3 2005.