in my view there should be a clear purpose to sending the email out I would say for an example making a sale or providing information or selling your e-book/ bringing back to them on your blog to your audience about the subject matter expert that you are..we need to think in their point of view,provide value first and then ask for sale......

Sale is a huge commitment on customer’s part..get them to commit to you slowly and avoid any factors that will scare them away..such as offering free shipping, refund guarantees and satisfaction guarantees. gotta go...thats all for today.