Maintaining a German B2C list requires scheduled verification, not reactive fixes. For active campaigns, verify lists every 30–45 days; for cold outreach, verify before every send . Remove hard bounces immediately after each campaign. Process unsubscribe requests promptly—German competition law requires a functioning opt-out mechanism. For T-Online addresses, do not blanket-suppress b... https://www.b2cemaillist.com/germany-b2c-email-list/