SPAM attacks have declined as malware writers are using new approaches (e.g., malicious web sites, mobile phones, etc). Still, there is danger in processing email as approximately 2/3 of all email traffic is spam or malware based. Some excellent analytical reports by Kaspersky below:
QUOTE: According to Kaspersky Lab data, the share of spam in email traffic decreased steadily throughout 2012 to hit a five-year low. The average for the year stood at 72.1% – 8.2 percentage points less than in 2011. Such a prolonged and substantial decrease in spam levels is unprecedented.
The main reason behind the decrease in spam volume is the overall heightened level of anti-spam protection. Spam filters are now in place on just about every email system, even free ones. Also, many email providers have introduced mandatory DKIM signature policies (digital signatures that verify the domain from which emails are sent). Another factor behind the falling levels of spam is inexpensive advertising on legal platforms. With the emergence of Web 2.0, advertising opportunities on the Internet have skyrocketed: banners, context-based advertising, and ads on social networks and blogs. In spite of the drop in the overall percentage of spam in mail traffic, the proportion of emails with malicious attachments fell only slightly to 3.4%. .
Kaspersky – full Spam Report for 2012