On Sun, Mar 05, 2023 at 08:50:24PM +0000, ael via Exim-users wrote:
> > Your debug shows SMTP-leve success responses for both the data
> > phase for the message and the SMTP QUIT after it.
>
> Thank you for confirming what I had suspected: the messages are
> essentially spurious, although perhaps revealing that some SMTP
> servers don't close properly: the usual suspects.. :-)
Because SMTP has application layer protocol message framing (SMTP
commands and responses), there is no need to lean on TLS to defend
against message truncation. Since process and connection slots are a
finite resource, many SMTP do not bother with SSL shutdown, and just
tear down the TCP connection immediately after sending the "QUIT"
command or response.
Exim would ideally not log TLS errors related to connection tear down,
they have no relevance to SMTP.
--
Viktor.
