Return Path is expected this week to introduce a beta of its reputation scoring system, called Sender Score, to help marketers determine how recipients perceive the email that the marketers send, ClickZ reports. The subscription service examines various data sources to rate the reputation of senders. According to the company, the system is compatible with email authentication efforts such as Sender ID and Yahoo/Cisco's DomainKeys Identified Mail.

However, a Return Path spokesman said the idea behind the new program is not to determine merely who senders are but to rate them: "This kind of credit score model is really the only way to get at what's a complex question, which is, 'do I want mail from this guy?'" To come with such a score, Sender Score aggregates 60 data points based on information from some 40 million email boxes - including complaint data, email send volume, bounce volume, security practices, identity stability and unsubscribe functionality.

The subscription fee is $1,000-20,000 a month, depending on the complexity of the senders' systems. The company is now testing Sender Score with some of its clients. A full release is expected in August.