On 31/08/20 4:58 am, Nick wrote:
On 2020-08-09 21:52 BST, Ansgar Wiechers wrote:
On 2020-08-09 Nick wrote:
For mail sent via submission it's possible to prevent a forged
mail-from, by using options on the submission service in master.cf.
It's also possible to prevent a forged header-from, by using a
submission-specific cleanup service, as in the BUILTIN_FILTER_README.
But these don't work for mail originating locally via the sendmail
command. What does work for that?
Nothing. The sendmail command submits mail via pickup, i.e. puts it as a
file into a particular directory from which the pickup daemon then reads
the file. The usual filters don't apply to that.
What you can do is disable pickup entirely so that even local users are
required to submit mail via SMTP (on localhost).
Thanks. I have an idea which is probably infeasible...
In the OVERVIEW document, the path for local sendmail is shown as
sendmail(1) -> postdrop(1) -> maildrop -> pickup(8) -> cleanup(8) ->
incoming
I would like to have a postconf(5) parameter such as
"local_via_submission = yes" which changes that path to something like
Just grab a copy of msmtp and have it submit to the localhost submission
service. Use the sendmail binary from msmtp instead of postfix's
sendmail binary.
Peter
