Microsoft said last week it plans to promote adoption of the Sender ID e-mail specification and introduce a new program for helping customers protect the integrity of e-mail messages.Citing research figures from MarkMonitor, Craig Spiezle, director of technology care and safety for Microsoft, said that the use of Sender ID among Fortune 500 companies increased from 7% in July 2005 to 21% today. About 32% of all e-mail sent is Sender ID-compliant, Spiezle added.Sender ID was developed by Microsoft, SendMail and other companies as a type of caller ID system for e-mails, he said. The IETF is working to develop the Sender ID specification, the first draft of which was released in June 2004.Sender ID lets companies attach information to an Internet domain that tells e-mail recipients what addresses are authorized to send mail from that domain, Spiezle said. This lets the system receiving the message recognize whether it is legitimate or being spoofed by another domain, he said.Once companies adopt the Sender ID protocol, they can gather information about which e-mail addresses are legitimate and which are not, and create better filtering for their inbound e-mail systems, Spiezle said. They also can decide to block e-mail from legitimate addresses that are not useful to them."The first [phase] was getting systems in place to check the validity if the mail has been spoofed or not," he said. "Then you can build reputations based on what users are saying and apply that to overall scoring of the mail."MSN Postmaster Services is aimed at helping with this second phase. The program provides information, best practices and tools for helping ISPs better manage their e-mail infrastructure for serving MSN and Windows Live mail users, Microsoft said.It also offers Smart Network Data Services, which provides reports on how well MSN and Windows Live Mail e-mail filters are processing messages. This tool can be used to find and stop computers that are sending spam, the company said.Another feature of MSN Postmaster Services is a detailed overview of the MSN and Windows Live Mail junk-mail filtering processes and guidelines to help improve how well organizations deliver to MSN Hotmail and Windows Live users, the company said.MSN Postmaster Services is free and available only in English, though Microsoft plans to add more languages.