1. Send select targeted strategic hard copy mail to a well-managed list.
2. Practice Permission Marketing.
3. Follow the guidelines of the CAN-SPAM Act.
4. Regularly (quarterly, as instance demands) clean and manage your mail, email, etc. lists.
5. Only send email solicitations to people you have met and have express permission to email. See #2, #3…
6. ONLY send large materials like catalogs if requested and properly vetted.
7. Protect and respect the privacy of your lists by never selling, renting, sharing or giving this sacred info to others.
8. Only send mail (hard copy + electronic) if you have a specific and properly spelled accurate name.
Business is built on relationships. Build the relationship first, then market later.
Reference: How NOT To Market To New Customers here.