- SMTP Address Validation: Bad Idea. What is it? How does it work? Why do ISPs hate it?
- Email Address Validation: Options. In this followup, I share with you some address validation do's and don'ts. How to maximize list hygiene without running afoul of spam filters.
If you're wondering what SMTP email address validation is, why it is a bad idea, and what your options are, check out my short series on the topic: