If a bot already scraped the site, the email addresses are already in spam lists (likely every email was already in spam lists). To answer your question, here are several options…
The first option is to set all email addresses as private or unlisted. This will keep the email addresses from being displayed publically. Only logged-in users can see them if you set them to private.
The second option is the ROT13 Email Encryption addon. Here’s the link to the addon with more details:
This applies some obfuscation to the email address. It appears correct/readable in the browser for visitors. The obfuscation is an attempt to foil harvesters.
The third option is the Contact addon. Here’s the link with more details:
This addon hides all email addresses regardless of their visibility status and allows visitors to send an email using an on-page contact form.
I hope this helps; please let me know.
