I have a concrete block home with EMT pipe. I would like to install a flush-mounted outlet on an outdoor wall by passing a pipe from an adjacent indoor outlet.

Can I use a standard EMT outlet box with a standard mudring followed by reapplication of stucco, paint, and a liquid-tight faceplate?

Or do I have to use a liquid-tight outlet box?

Thank you.

As long as you are sealing up around it with finish surface a standard box is fine. No WP box is required because it will never be wet.