Use Rules to Change Field Value By Clicking URL I am creating a simple internal ticketing system which emails customers when the status of their ticket changes (Open -> Waiting on parts). I have set up rules to do this and I haven't had any issues with it. However, I would like to create a way for customers to "unsubscribe" from the emails. I have created a checkbox field named "allow emails" which determines if customers will or will not get an email as a condition for the rule.

I would also like to include a link at the end that if clicked the customer would set the field to "no" or "off". 

Note:Customers aren't actual users on the site but are nodes within a "customer" content type. The users are our internal staff that would log in to use the website.

Can rules do this by itself or do I need a separate module?

Thanks
I'm not sure I understand exactly what you need, but the great module Rules Link (https://www.drupal.org/project/rules_link) provides a link that can be attached to any content type or entity, and can also be accessed in Views as a special Rules Link field. When you click the link a preset Rule is triggered. The link passes the node or entity as a parameter to the Rule. There is also the option of using a "Javascript" link that invokes the Rule via AJAX (without reloading the whole node) - I've never used that option, but I suspect that it may help your needs.