Preparation is cheaper than a damaged sending reputation. The checks happen before the first message, which is the only point they are worth anything.
Matching
Reconciling what you hold against what is current, with disagreements surfaced rather than silently resolved.
Repeatability
The same brief run twice produces the same file, because the definition is recorded.
Correction
Updating what has changed, wherever a current value can be established.
If mail is not arriving, we will look at the configuration and say what we find.