FOLIO sends notices to patrons from a single reply-to: address, configurable on the tenant level.
This is also the address that is used when sending password reset emails to staff users.
Some libraries may be coming from systems where they are used to being able to send emails to patrons from different reply-to addresses, depending on where the item was coming from. For example, patrons with items from Main library got emails from main-library@duke.edu, while patrons with items from the Science Library got emails from science-library@duke.edu. This is not possible in FOLIO as of Iris