Suppression, consent state and exclusion lists get applied before delivery, not as a correction afterwards. A record you asked to be withheld stays withheld.
Sending identity
Separating what you send in volume from how your main domain is treated.
Residual questions
The parts of a brief the data cannot answer, returned as questions rather than guesses.
Decay review
Identifying the records that have stopped being current, and how many of them there are.
Ask for the sample before the build. It costs nothing and settles most questions.