An extra 23 Fortune 1000 companies used the standard over October, highlighting an industry shift towards authentication.
"This adoption of Sender ID is a testament to the broad industry and business commitment to email authentication," said Craig Spiezle, director of Microsoft safety technology. "It's critical to reassuring consumers' online confidence while protecting the brand and reputation of businesses."
Authentication has become an industry weapon in fighting the proliferation of phishing emails. It requires domain verification of email senders, preventing messages claiming to be sent from somewhere they are not.
The Federal Trade Commission (FTC) recently held the first Email Authentication Summit in Washington DC. At least five standards were submitted, including Yahoo's DomainKeys and Cisco's Internet Mail. During the summit 36 companies, including Amazon, Ciphertrust and eBay, presented a letter to the FTC supporting the development of email authentication.
"Businesses around the world face the risk of having their brands hijacked and then used by phishers and spammers to victimise their own customers," said Paul Judge director of research and development at email security company CipherTrust. "Every enterprise should make it a priority to safeguard their brand and customers."