Jacob Palme <jpalme(_at_)dsv(_dot_)su(_dot_)se> writes:
At 20.56 +0200 04-08-17, Kai Henningsen wrote:
... when using the -t option.
I do not understand this "-t" option. "-t" looks to me like
a Unix shell command parameter.
It is.
I thought that MUAs
communicated with MTAs for outgoing mail using the SMTP
protocol or a variant of SMTP adapted for communication
between an MUA or the first MTA, and not by using a
unix shell interface.
They do.
But in Unix world MUA-Part1 can commumicate with MUA-Part2
via a pipe, like:
cat message | /usr/lib/sendmail -t
This is using cat/sendmail pair as a MUA.
sendmail instance could do MTA job as well,
or could open socket to ANOTHER instance of sendmail as MTA
and talk SMTP over that socket.
Is "-t" an ESTMP facility?
No.
How, otherwise, can the MUA tell
the MTA that it wants the MTA to remove Bcc headers from
non-Bcc recipients?
The summary just posted explained that MTA has no bussiness
removing Bcc headers. It is a MUA function that happens, on
Unix, to be implemented by another instance of sendmail
binary invoked a particular way.