Yes, and the process is built directly into your InmateAid account.
When you send a letter through InmateAid, the return address on the envelope is InmateAid's Florida address. Your inmate writes their reply on paper, addresses it to that Florida address, and mails it out through the facility's regular outgoing mail with a postage stamp. InmateAid receives the letter, scans it, and places it in your account under a section called Inmate Response Letters in your Account Dashboard.
You will receive an email notification when a reply is waiting, then simply log into your account and retrieve it from the dashboard. The incoming letter appears as a PDF you can read and download. The fee for retrieving an inmate response letter is $1.49.
The system works in both directions by design. Your home address never appears anywhere in the exchange. Your inmate writes to InmateAid's Florida address rather than your personal address, which keeps your location completely private throughout the entire correspondence.
Your inmate does not need an account, does not need internet access, and does not pay anything to InmateAid to participate. The only cost on their end is a postage stamp for the outgoing letter, which most facilities provide to inmates who have no funds on their books.
Check your Account Dashboard after sending your first letter and look for the Inmate Response Letters section. That is where everything from your inmate will appear once they write back.