I get a warning from Avast every time I click on a QB link gotten through a search. FYI, here's what it says the problem is:
[TABLE="class: lineone"]
[TR]
[TH]Infection:[/TH]
[TD="class: p_vir"]HTML:Script-inf[/TD]
[/TR]
[/TABLE]
As for e-mails going into the spam folder, your e-mail service is seeing something about the e-mail that makes it suspicious to them. From input on other groups I belong to, I'm not sure you can get it through their thick heads that these e-mails aren't spam to you. Good luck!