There are already many good solutions for email marketing to reach thousands of people. For that kind of marketing, it makes sense to have a clear unsubscribe link. Cold outreach might be a gray area, where we want the recipient to believe that we are sending them a personal email, but we may be sending many of these emails to many people with an automated sequence.

I believe that there are small scale cold outreach, and automated engagement of clients where it would be appropriate to leave out the unsubscribe link.

I am trying out one similar tool that does not include the unsubscribe link, and it works for what I need it to do. Another cold outreach email tool I tried only sent emails with an unsubscribe link, and that made no sense to me, because I already have access to marketing tools that do that.

Your approach is intriguing, allowing the email reader to apply with specific keywords to indicate that they do not want to receive emails.