Handshakes explained
How both companies confirm the same fact, and what happens if one side goes quiet.
A handshake is a specific fact both companies confirm: this date, this weight, this delay. It exists so neither of you can later be unsure whether the other knew.
It is between organisations, not individuals — anyone with the right role can shake for their side, and it stays valid when that person leaves. There is no un-shaking; once both sides agree, that is the record.
Each side has an auto-resolve window, set in Settings and defaulting to forty-eight hours. If one side never responds the handshake resolves itself and is marked auto-acknowledged rather than mutually shaken, so the record shows the difference. A silent partner can never block you indefinitely.