I am looking at Mailing Lists.

At present, the user can use an unsubscribe link, and if successful, the user's email address is deleted from that list.

I am planning to integrate this with an API.  It would be great if the user was marked as unsubscribed with a date and reason why they wished to unsubscribe.

This could then be pulled into other systems via the API to allow proper management and integration of that list with other systems.

I currently would have to check who is on the list, who isn't and act accordingly whilst assuming the reasons for their departure.

I also notice from the subscriber information that you can see what they are subscribed to on the current domain.  Should they be offered the ability to opt out of all mailing lists from with SmarterMail?  Sort of a preference centre, particularly in the light of GDPR in the EU.