Spam is once again on the rise, and this time it's apparently being fueled by spam vendors that can't scale. That's the accusation being leveled by Google, which today revealed some surprising new spam figures.

The fight against spam has increased in traction for Google (NASDAQ: GOOG) with the acquisition of vendor Postini for $625 million last year.

Time of year plays a role in the increased volume of spam seen in July, according to Sundar Raghavan, a product marketing manager with the Google Apps Security & Compliance team

"Historically every summer there is increased activity in terms of spam volume, but the sophistication they are using this time around seems to be more robust," he told InternetNews.com.

"Between July and August we have started to see a very interesting pattern in term of volume and sophistication of e-mail threats incoming," Raghavan said. "Around July 20 we started seeing a spoofed UPS tracking e-mail messages going to users. On July 24 saw a peak of 10 million messages."