The consensus is that including a "you've received this email because..." message or similar explanation is generally a good practice, especially in contexts like COVID-19 related emails, onboarding sequences, and within GDPR guidelines. It enhances transparency, builds trust, reduces spam complaints by reminding subscribers why they're on the list, and sets expectations. However, relevance and clarity are paramount: the email's purpose and the recipient's benefit should be immediately clear. This message is not a substitute for core email practices like authentication (SPF, DKIM, DMARC) and list management. There is a caution that certain phrases related to this may have triggered spam filters in the past, and a suggestion that alternative messaging or disclaimers may sometimes be more effective.