The latest monthly statistics from Postini note how over 23Bn messages were processed during March, of which unwanted email totalled nearly 19.6Bn. This equates to a 4% increase on February, bringing the total amount of SPAM to 84% (16% = legitimate).

The company also filtered 6.5 million IM conversations in March, an increase of more than 200% over February’s 2.2 million, underscoring the growth of corporate IM.

While unwanted email was on the rise, viruses declined by 19% of all email in March, with Postini stopping a total of 32.5 million viruses. The top five viruses for March were:

Virus Name - Quantity Blocked
1. Mytob - 16,742,504
2. Netsky - 5,289,158
3. Mimi - 2,669,122
4. Lovgate - 1,633,323
5. Bagle - 1,179,221

Postini protected its customers from more than 15 billion directory harvest attacks (DHAs), malicious attacks and email to invalid recipients, a seven percent increase over February’s 14 billion.

Interestingly our own survey notes how just 16.9% of ISPr’s readers receive no spam, which is very close to Postini's figure.