You can’t re-add someone who has marked you as SPAM, but you CAN send them a link to your signup form so that they can re-opt in!
You can only do this for any particular contact ONCE every 30 days. If they mark you as spam more than once in this period and want to be re-added, they will have to wait until the 30-day period has passed before this button can be used again. Alternatively, you can email them the link to your signup form as a workaround.
1. Locate the email address that has marked you as spam or has requested to be re-added. You can do this by going to Reports > Campaign Overviews and clicking on the number in the SPAM column for the campaign you’ve sent, or you can search for the email address under Contacts.
2. In your Contacts, click the email address (if you click on the email address from Reports, you don’t need this step):
3. Click Resend Opt-In. This will resend the opt-in link to that person directly: