Tom Sommer:
> On 2021-01-17 17:29, Wietse Venema wrote:
>
> >> On 2021-01-17 14:22, Wietse Venema wrote:
> >> >> I just observed Postfix not picking up changes in the SASL auth
> >> >> backend,
> >> >> is there some kind of cache involved here?
> >> >
> >> > There is no such thing in Postfix. Also not in the Postfix Dovcecot
> >> > client.
> >>
> >> Curious, and it couldn't be connection cache/reuse or something?
> >
> > Your Postfix SMTP server logs would contain one smtpd 'connect'
> > event with multiple smtpd "QUEUEID: client=name[address]" events.
>
> That's basically what I see. A few connect-events and a ton of
> "sasl_username" client-events. So the same connection is being reused by
> the client to just keep the connection open and send mails, bypassing
> any password changes or account deletion. Is there some way to prevent
> this? Perhaps have the connection die after 10 seconds, forcing a
> re-auth?
There is no defined behavior for doing this in SMTP. you may be
able to configure Postfix with postfwd etc. to reply with 421
(forcing Postfix to hang up), or to the same using Postfix's built-in
smtpd_client_message_rate_limit feature.
Wietse
