Jobs at small Tulsa companies nobody posts about (Tulsa)

Two small Tulsa employers told me they are hiring but have not posted yet. I worked as a paralegal before this. They like a brief email with a résumé. What do you write in a cold email?

A short email with two sentences about what you can do and your résumé attached worked for me. I followed up after a week.

Visiting in person worked for a trades job. For office jobs, email was better.