Jobs at small Richmond companies nobody posts about - first time posting

Two small Richmond employers told me they are hiring but have not posted yet. I have read a lot of threads here and could not find my exact situation. One is a print shop, one is an accounting firm and one is a clinic. 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.

Keep everything in writing and save the confirmation numbers. It saved me later.