What does M3AAWG recommend for list collection?

M3AAWG recommends confirmed opt in (double opt in) as the preferred method for list collection. Their Sender Best Common Practices document emphasizes verification that the address owner actually requested subscription.

Additional M3AAWG recommendations include clear disclosure of what subscribers will receive, transparent frequency expectations, and easy access to privacy policies during signup. Consent should be specific to email, not bundled with other agreements.

M3AAWG also recommends against purchasing lists, harvesting addresses, or using pre checked subscription boxes. These practices generate complaints and deliverability problems regardless of technical compliance with other standards.