…tely. Clients MUST implement the certificate validation mechanism described in [RFC7817]. Once the TLS session is established, POP3 [RFC1939] protocol messages are exchanged as TLS application data for the remainder of the TCP connection. After the server sends an +OK greeting, t…

…ely. Clients MUST implement the certificate validation mechanism described in [ RFC7817 ]. Once the TLS session is established, POP3 [ RFC1939 ] protocol messages are exchanged as TLS application data for the remainder of the TCP connection. After the server sends an +OK greeting…