Are you using the Unsubscribe option?
If you send a single email a standard footer can be appended such as Company name registered office to ensure compliance with regional and industry specific regulations.
When sending multiple emails a alternative footer is appended to allow recipients to unsubscribe.
Optionally you could include the facility to update the users details or to view their own details whilst not being able to edit certain fields. Either way the Unsubscribe option can lead to a high degree of compliant automation.
Ask for details in most cases this is set up for free.