Top Deliverability’s Blog
Spam Resource: Wombatmail COI/DOI update: Now with reCAPTCHA!
Al Iverson just released a new brilliant blogpost on Spam Resource:
Verifying email addresses through methods akin to what we now think of as confirmed opt-in (COI) or (DOI) isn’t a new thing. Mailing list software Majordomo added support for verifying new signups way back in 1996. I don’t remember exactly when it became common to validate that opt-in via an email click, but I remember building email click tracking — sending out a unique indicator per subscriber and taking action or updating a status — for my own purposes way back in late 1997 as part of a spam filtering system I had built at the time. Then in 1998 I started a COI/DOI email list for my friend’s jazz club using custom code (not captured by the Internet Archive until 2001). So, it’s been done before.
