@KISSmetrics
This is a great tutorial for how you can keep your emails from getting tagged as SPAM. As a side bonus, these techniques will also help get more of your emails read by your prospects.
I especially like "Sending emails onec every two or three months can be more detrimental than sending multiple emails dialy. Why? Your customers may forget all about you."
I especially like "Sending emails onec every two or three months can be more detrimental than sending multiple emails dialy. Why? Your customers may forget all about you."