With great power comes great responsibility. Just as you can reach many customers with direct mail marketing, so you must treat them respectfully. This means following a network of common-sense ethical guidelines and firmer laws and regulations that keep direct marketing honest and above board. Be transparent. Don't lie or obfuscate about who you are or what you're selling. Share a real, physical street address as a return address. This ensures you can be contacted.
The authorities if you have broken executive list laws, and allows consumers to contact you for removal notices. Speaking of: Let customers opt out. Some customers don't want to hear from you, and that's okay. They have the right not to receive your communications and you have a right to save your money and not send to them. If you have a request to be removed from the mailing list, take action within 30 days to stop mailings. Follow the Do-Not-Mail List. Here's where things get tricky.
A national opt-out list curated by the DMA. This allows customers to opt out of certain categories of direct mail (for example, credit card offers) or "all" direct mail. Notice the quotation marks. This list only applies to unsolicited direct mail. In other words, if you've never had a business relationship with that person, you shouldn't send to them if they're on the list. However, if they're a former customer, you're still fine. However, some cautious marketers choose to cross-index even.