as I understand it.
Postal votes are delivered ...by post.
The envelope is signed on the outside.
The signature is checked against the enclosed signed ballot paper.
The envelope is thrown away, but counted.
The signed portion of the ballot is torn off
the ballot is counted
all numbers are cross checked and tallied.
Voting in person
People arrive, not sure how id is checked. (not mandatory - as in the uk)
The voter uses a machine to cast a vote, it prints a paper vote
The voter then feeds the paper into another machine, where it is scanned and recorded/tabulated.
So they have a record of votes cast, and two records of partisan votes. All three must match.
All the machines do is count or print.
They are not web enabled.
The memory is a secure unit.