In a message written on Tue, Feb 02, 2021 at 10:15:49AM -0500, Viktor Dukhovni wrote: > There is no problem, both sides send a "close_notify" alert when closing > their "write side" of the transmission channel. So neither reader will > ever see an abuptly lost connection. However, keep in mind that TLS or > no TLS, Postfix will by default close the connection after sending > "QUIT": > > smtp_skip_quit_response = yes > > *without* waiting for the "221" response from the server. Which means > that servers may encounter write errors when sending "221" or the > subsequent TLS close_notify. The best thing to do in that case is > just ignore the error, and not waste the administrator's time chasing > ghosts.
I won't attempt you change your mind, as you've clearly made it up. However, in my role as an admin, you just gave me excellent justification to never run Postfix. The shutdown aspects of protocols should not be optional. Clean shutdown at the TCP, TLS, and SMTP layer provides confirmation the software is working properly. When debugging, via logs or tcpdumps a proper shutdown sequence provides quick confirmation that all was well -- where as intentional incomplete sequences provide an provide an endless stream of dead ends to chase down while hunting for legitimate problems. I've made the community aware of my findings. I cannot force the Postfix community to fix them. I won't attempt any further, thank you for your consideration. -- Leo Bicknell - bickn...@ufp.org PGP keys at http://www.ufp.org/~bicknell/
