How can I unsubscribe an email address from my list?

The easiest way is when the recipient clicks on the unsubscribe link in one of your mass emails.

An unsubscribe link is inserted into every mass email. If a recipient clicks on it, they will not receive mass emails from you anymore.

MiniCRM checks it every time. You are only allowed to send unique emails to those who have unsubscribed.

You can even do this by yourself on the Unsubscribe page.