Jumping in as an observer with 25 years of admin experience with public facing equipment and servers. this problem seems more of a problem with the tls libraries. it’s not up to the app to close the tls connection. that layer is below the application layer. when the application terminates its connection the tls library should be smart enough to close the socket properly itself. this seems to be a problem of the tls layer not playing nicely with its peers. the smtp protocol is clear about its connection termination handshake. it doesn’t seem like the tls layer is.
just my $0.02 -Curtis Sent from my iPhone > On Feb 2, 2021, at 10:31 AM, Bill Cole > <postfixlists-070...@billmail.scconsult.com> wrote: > > On 2 Feb 2021, at 9:49, Leo Bicknell wrote: > >> Perhaps Postfix does not support returning to clear text from a STARTTLS >> session and doing futher protocol operations. I have not looked. But if it >> does, I believe the proper shutdown behavior is a MUST. > > No SMTP server should ever support downgrade of an established STARTTLS > session to clear text. > > -- > Bill Cole > b...@scconsult.com or billc...@apache.org > (AKA @grumpybozo and many *@billmail.scconsult.com addresses) > Not Currently Available For Hire
