Deploying static content not updating css

As far as I understand it, In order to change the style of an email, I need to override the _email-extended.less file. I go to the path below

app/design/frontend/Smartwave/Porto/web/css/source/_email-extended.less

and make my changes/add classes but it doesnt seem to affect any of my generated static content css files. It simply does nothing. Ive tried deleting the folder where I assume it shows up

pub/static/frontend/Smartwave/porto/en_US/css

but when I look, none of the files have been modified, it still generates the same files it was before it got deleted. The best i can tell is im doing the changes in the wrong location, however i am not sure where to look if not in the directory listed above…