If you've done any email marketing at all, you've no doubt received "spam" complaints. Even if your list is double opt-in.

For whatever reason, people sign up for your newsletter, confirm they want it and then report it as spam.

Well, James Brausch wrote a post on his blog recently that has an excellent tip for avoiding 90% of these spam complaints.

You see, that 90% (probably higher, actually) comes from free email services like Gmail, Hotmail, and AOL (the worst by far in my experience). They just make it too easy to report a message as spam - usually a single click and that's it. No following up with the sender, no way to prove to them you're not sending spam.

If you've used Google Adwords at all, you're probably familiar with negative keywords. These are words you don't want your ads showing up for.

Well, James has a similar idea for your opt-in lists - a "negative email address" list. You can read all the details in his recent post Building A Quality List.

Don't be afraid to weed out useless signups. You may not be able to brag about the size of your list, but you'll be more likely to brag about your conversion rate.