How do I delete a subscriber list?

Deleting a subscriber list is easy.  You can delete a list in either Salesforce or Campaign Monitor.  We recommend deleting it from Salesforce as the process is started immediately, this article shows how. If you delete a list in Campaign Monitor the primary sync needs to run before the process can be started.

When you delete a subscriber list it does not affect any standard records like contacts or leads.  It will however remove the subscriber list and list member records from both Salesforce and Campaign Monitor.  Additionally, if you have any field mappings, import wizard, or subscriber rules set up for this list they will also be removed. If you have a lot of subscriber list members the process can take a few minutes to complete.  

Email tracking history and Campaign Monitor campaigns are stored separately so even if you delete the associated subscriber list this information won't be affected.