What kind of software to you use to send email campains to your client base?

Todd, I have been using Intersend.com for years. Since 1999. I have customized my letters, short and sweet. If you can't stay on top of your leads you need a drip campaign. With the amount we get from PPC campaign we have to have it. At least they are hearing from us on a regular basis, because you know they are out still looking. 

There is many campaigns in the package, buyers, internet buyers, sellers, sellers under contract, relocating letters and after the sale letters. I pay 29.95 per month. Hope that helps. You can try it free I think for a few months.