PN Spam filtering is it OK

[#1]

Not that I get that much but the messages that contain, what is to me clear spam, seem to be on the up. Today I received two such with very similar content, as per the source details on the attached  pdf.

[#2]

Unfortunately what to a human might clearly be spam isn't necessarily scored that way by a scanning system, and the messages *could* be something the recipient has requested. The originators will take care to craft their messages in a way that makes detection harder. Both messages come from Hotmail servers with good reputations, presumably generated and sent from compromised computers.
Hopefully Hotmail themselves will detect the sending activities and stop them. I expect IronPort too will in a short time adapt their filters to recognise and flag this style of message.

[#3]

Thanks