Microsoft last week verified it is significantly throttling the volume of e-mail it will allow to come into its Hotmail accounts from new IP addresses.
“If we’ve never seen mail from you before, we’re going to limit the amount mail sent to us,” said Craig Spiezle, director of online safety at Microsoft Corp. “The message to the marketer is: ‘You want to be cautious. Don’t do your major holiday campaign, and on day one, drop a few million mails from a new IP address.’”
When asked how strictly Microsoft throttles e-mail coming from new sources, Spiezle said: “It’s going to be severely throttled.” He declined to get more specific.
He added, however, that a new IP can gain a reputation with Microsoft that will allow the sender to deliver e-mail at full throttle within 72 hours to a week.
“What we want to see is if we let in x amount of thousands of mail, do we get any complaints?” he said. “And then if we double it, do we get any complaints.”
He also refused to get specific about how many e-mails a day a mailer should send from a new IP in order to build its reputation, but indicated 50,000 to 100,000 might do it.
Many suspect Yahoo! is also throttling e-mail from new IP addresses, as well, but won’t own up to it.