Free open-source desktop mail client for ordinary email and Italian PEC/REM. It talks IMAP, POP3, and SMTP to the mailbox you already hold at a QTSP or ordinary provider, and keeps the archive on this computer.
This app is not a qualified trust service, not a PEC operator, and not a timestamp authority. Receipts and envelopes come from the gestore; Postclient shows them.
First packaging slice: self-contained Windows setup and Linux Flatpak. Product name is a placeholder until the public sign is registered.