Define the order of operations#
Apply unsubscribe, complaint and permanent-failure rules before preparing an audience. A mailbox can be technically reachable while being inappropriate to contact. Keep permission and reachability as separate fields.
Test the actual unsubscribe path#
Use a controlled subscription to exercise both the visible unsubscribe link and supported list-unsubscribe behavior. Confirm that the result reaches every sending system that can contact that person. A success page alone is not evidence of a completed suppression.
Protect the state during imports#
Make consent and suppression fields authoritative when reconciling CSV results or CRM updates. Record who changed a status and why. Never let a generic “valid” verification value overwrite an unsubscribe. MailMaid cleaning outputs leave that policy decision visible to the operator.
Primary references
Consult the current specification or provider guidance when applying these checks.
One-click unsubscribe specificationGmail sender guidelines