I get so much spam at my main personal email address that I no longer check the spam folder to check for false positives. Over the past month I've received over 7000 spam emails there.
Handily, I'm running Google Apps For Your Domain on steve-lacey.com, and the spam filtering is very good. I'm not just saying that because I work for Google, I'm saying that because it works.
For the first month of using GAFYD, I checked my spam folder every day and had no false positive, while the email that got through the filtering had next to no spam.
That's pretty good in my book.
Today I found out about email from a friend that had been marked as spam, I searched in the spam folder and found it.
But that doesn't mean that I'm going to go back to looking through that folder every day. It takes too much time.
So, if you sent me something and I haven't responded in my normal timely manner, either try again, or just pick up the phone and call me at +1.425.466.9305.