Are You Sending Opt-in E-Mails or Spam?

Simply put, opt-in e-mail is e-mail sent to people who have given the person permission to contact them via e-mail on a particular subject. It builds on existing relationships with customers, newsletter subscribers, affiliates and sales leads. This is why opt-in e-mail is sometimes referred to as "Permission-based" e-mail marketing, and it's the most critical element to take into consideration when launching an e-mail campaign.