Checkout Geobytes' Message Keys technology
Ask Google what their "Lost Message Rate" is, as opposed to their "False Positive Rate".
The "Lost Message Rate" tells you what proportion of non-spam messages are being gobbled up by the spam filter. While on the other hand, the "False Positive Rate" is more of a reflection of the amount of spam you are getting - as the more spam you get, the better the "False Positive Rate" gets - even thought you may be loosing the same number of non-spam messages.
In any case, fortunately it is easily fixed. Just in a key in your email address itself - which might look something like this:
"John Smith -12345" <joHN.SmiTH -12345@eXamPLE.Com>
OK - Google currently won't let you do this, but that is another issue.
More here: http://www.geobytes.com/message-keys/
Biting the hand that feeds IT
