> On 24 Nov 2019, at 03:42, Gianni Angelozzi <gianni@sistema3.it> wrote:
>=20
> In my system I have 10 users. Each user has his own upstream account =
on the ISP.

If you mentioned that before, I missed it.

> 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.

In that case you do need smtp_sender_dependent_authentication (though I =
would go with a different provider or not run my mail server on a home =
connection).


--=20
'It's vital to remember who you really are. It's very important. It
isn't a good idea to rely on other people or things to do it for you,
you see. They always get it wrong.' =E2=80=94Sourcery