Force TCP socket disconnect on imap login failure?

[Stuart Henderson]

On 2022-05-24, Hippo Man <hippoman at gmail.com> wrote:
> * Hacker makes numerous login attempts one after the other with various
> passwords, and without disconnecting in between attempts. I've seen 10 and
> more of these repeated attempts rapidly during a single imap or pop3
> connection.

"numerous" and "rapidly" sounds wrong; between auth_failure_delay (in a single
connection) and the penalty mechanism for all connections from an IP address
(https://doc.dovecot.org/configuration_manual/authentication/auth_penalty/)
it should soon get beyond "rapidly".

Is there something in your config that disables this? Or is your idea of
"rapidly" just different to mine?