Add unsubscribe link to emails

Hi there
In order to comply with GDPR regulations and avoid emails being sent to spam an unsubscribe link is required in the body of the email. I use the plugin WP Mail SMTP to deliver emails so I asked their support if this is something that can be implemented on their end and they said the link would need to be added by the plugin/service initiating the email. So I was wondering how would I add this to my emails and how would I create a functioning unsubscribe page that the users who click the link will be directed to.
Any help would be greatly appreciated

Hi,

Unfortunately, we don’t have this feature. If you need it urgently, we recommend considering third-party SMTP plugins that support this feature.

​I hope this is helpful to you.