In my system I have 10 users. Each user has his own upstream account on
the ISP.
I use postfix + dovecot + fetchmail as a local mail server, but the real
sending is done by my ISP. I only forward local mails and the rest goes
out by the ISP.
When I authenticate the SMTP connection, my ISP will only allow that
user to send the mail. Like, if I use user1 credentials as the default,
then user2 won't be able to send mails. They will bounce back.
Isn't this is the reason smtp_sender_dependent_authentication is created
for?
Thanks for your help.
Gianni
On 23 Nov 2019, at 10:13, Gianni Angelozzi <gia...@sistema3.it> wrote:
Yes, I need smtp_sender_dependent_authentication because the upstream ISP will
only accept incoming mails from the authenticated user.
That doesn’t imply a need for smtp_sender_dependent_authentication. That is
needed, AIUI, when you have multiple senders on your system who all need
separate authentication.
Enable sender-dependent authentication in the Postfix SMTP client; this is
available only with SASL authentication, and disables SMTP connection caching
to ensure that **mail from different senders** will use the appropriate
credentials.
(Emphasis mine)
