The Email Wars

In a similar fashion to the Auditing The Opt In post, you need to always be checking that your opt out process is working. People make changes to code on your site(s) that can impact this flow.

Make sure to test the the footers or any links in your emails monthly.

Check that the opt out is processing immediately in your email ESP or CRM system AND any outside systems that you are using like Salesforce or MS CRM.

If you are syncing it with your ecom system make sure that they opt out is recorded there as well for marketing emails and that transactional emails are still working.

If you have a page on your site that allows to update or change your email profile, make sure that form/system is feeding the same data as the opt out.

The big red flag to me is to always look at any 3rd party data you are using and make sure to wash your internal database against it so that you are not emailing those that have opted out. I have seen my fair share of 3rd parties that email me and do not make this a solid practice.