The post office then has a record of it being received.
If there are more ballots mailed than there are registered voters, then fraud is evident.
If more ballots are stuffed into drop boxes at 0-dark-hundred, then there is no evidence.
—Unless there’s video of the perps...—
If more ballots are stuffed into drop boxes at 0-dark-hundred, then there is no evidence.
All absentee ballots are received, scanned and verified when they reach the clerk's office. It doesn't matter how they got there, the process is the same.
If there are more voters than are registered it will show up in the official counts.