Letters are marked as expired after 90 days of "in progress". They are "expired" for both members. They are not considered as "in progress" to the sender either.
They are still there and they can still be registered but they don't count as "in progress".
You as a recepient can view those incoming expired letters. In this way you know that you were soupposed to have received a letter and something went wrong with that letter.
Now when it is "expiered", you can mark that letter as "Not received" and if the sender is no longer active and does not mark it as "Mailed", then that letter will be canceled automatically after another 90 days. In this way you get your slot back to receive another letter.
