Spam, that annoying but ignorable scourge of the Web, has finally recovered from the jolt it received last November, when Internet backbone providers cut off McColo Corporation, a California Web-hosting service that spammers were using to coordinate e-mail attacks.

The average seven-day spam volume during the latter half of March is now at roughly the same levels as October of last year — around 94 percent of all e-mail — according to the antispam company Postini, a division of Google.

At first, the McColo takedown cut global spam traffic by about 70 percent, according to Postini, which provides e-mail security for more than 50,000 businesses and 15 million business users. “By far, it was the most dramatic event we have ever seen,” said Adam Swidler, product marketing manager for Postini Services.

But this year, average spam volumes have increased about 1.2 percent each day. And there is evidence that spammers are now building more decentralized, peer-to-peer spamming botnets that no longer rely on the visible and vulnerable control nodes that they were using at McColo to guide their spam e-mail campaigns.

“What the spammers have been using to rebuild is more technically advanced than what got taken out and is itself a more resilient technology,” Mr. Swidler said. “It’s unlikely we are going to see another event like McColo where taking out an I.S.P. has that kind of dramatic impact on global spam volumes.”

Postini is also reporting Tuesday on a new kind of spam called location-based spam. When gullible users click on a link in a spam message, they are directed to a Web page that contains a fake news headline and a purported video describing a nearby crisis, using the user’s I.P. address to identify the nearest major city. When the now curious and gullible users click on the video, their computer is infected with a virus.