CSP for Campaign Monitor Forms: Copy-Paste Reference
Campaign Monitor forms are simple until CSP gets involved. Then you add an embedded signup form, hit refresh, and the browser starts yelling about blocked scripts, frames, styles, or form submissions. I’ve had this happen enough times that I prefer starting with a known-good policy and tightening from there instead of guessing. This guide is the practical version: what to allow, what to avoid, and copy-paste CSP examples you can actually use. ...