According to Microsoft, 97% of all email traffic is spam (unwanted junk); mostly ads for pharmaceutical products. A significant percentage of junk mail originates in the U.S..
We recommend a multi-layer response to spam. A Shoestring-hosted web account can filter most email right on the server, before it ever reaches your inbox. Gmail has a pretty good spam filter; but if you view and archive your email on your PC, both the Windows Live Mail and Mozilla Thunderbird email apps include decent junk mail filters.
At Shoestring, we route all mail from Shoestring-hosted web sites through a Gmail (actually, Google Apps) account and view it locally with Thunderbird. We also use the Cloudmark Desktop addon, a very good spam filter. The four layers of spam protection keep our inbox almost completely clean, despite the fact that we receive several thousand in a 24-hour period.
According to Symantec, the volume of spam emanating from the US continues to increase. The US was responsible for 28 percent of all spam in March of 2009 (up from 25 percent in February and 23 percent in January), while Brazil held steady at nine percent and India dropped to four percent. Spam coming out of China has consistently dropped over the last several months as well, now resting at a mere three percent.
Microsoft: 3% of e-mail is stuff we want; the rest is spam – Ars Technica