Keep every single mail in ballot
Make each instance of fried it’s a five year prison term and then see what happens
Remember that with a mail in ballot do you have a date and time stamp on where it was sent from and a signature
A random sample of such ballots should be verified
Good news! They’re all verified!
Someone has to sit and match the signature on the envelope to the signature on record.
Be a boring job, but makes mail in voting secure.