localhost is blacklisted due to incorrect logins

[Former user]

hello,

on my poste.io's container all smtp,pop3,imap conntections see from localhost (172.17.0.1) ip :

Feb 26 20:35:58 ca70cf602ad2 dovecot: pop3-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=172.17.0.1, lip=172.17.0.2, TLS handshaking: SSL_accept() failed: error:142090FC:SSL routines:tls_early_post_process_client_hello:unknown protocol, session=<S5OfKtGCyIasEQAB>
Feb 26 20:35:58 ca70cf602ad2 dovecot: pop3-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=172.17.0.1, lip=172.17.0.2, TLS handshaking: SSL_accept() failed: error:1420918C:SSL routines:tls_early_post_process_client_hello:version too low, session=<74yhKtGC3oasEQAB>
Feb 26 20:35:59 ca70cf602ad2 dovecot: pop3-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=172.17.0.1, lip=172.17.0.2, TLS handshaking: SSL_accept() failed: error:141EC044:SSL routines:tls_construct_server_key_exchange:internal error, session=<sDiyKtGCl4esEQAB>
Feb 26 20:35:59 ca70cf602ad2 dovecot: pop3-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=172.17.0.1, lip=172.17.0.2, TLS handshaking: SSL_accept() failed: error:1417A0C1:SSL routines:tls_post_process_client_hello:no shared cipher, session=<eKG1KtGC5oesEQAB>
Feb 27 19:53:28 ca70cf602ad2 dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=172.17.0.1, lip=172.17.0.2, TLS handshaking: SSL_accept() failed: error:142090FC:SSL routines:tls_early_post_process_client_hello:unknown protocol, session=<k8d2sOSC8LGsEQAB>
Feb 27 19:53:28 ca70cf602ad2 dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=172.17.0.1, lip=172.17.0.2, TLS handshaking: SSL_accept() failed: error:1420918C:SSL routines:tls_early_post_process_client_hello:version too low, session=<nkp6sOSCOrOsEQAB>

because of this, the whole world (including my devices) it is automatically blocked by wrong connections:

[Former user]

URLs to images: https://postimg.cc/GTHn18zH https://postimg.cc/MXTSBNxq

this problem occurs on version 2.1.1 FREE

[Former user]

because it meant that I could not log in to webmail or administrator too, in nginx's config on container i need to add:

    set_real_ip_from 172.17.0.0/24;
    real_ip_header X-Real-IP;
    real_ip_recursive on;

what play good with my nginx on the front (in front of the container):

    location / {
        proxy_pass http://mailserver;
        proxy_redirect off;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_set_header Host $http_host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forward-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forward-Proto http;
        proxy_set_header X-Nginx-Proxy true;
        proxy_connect_timeout       10;
        proxy_send_timeout          10;
        proxy_read_timeout          10;
        send_timeout                10;

    }

someone also had this problem and knows how to solve it? (forward real IP addresses)?

[Scott MacDonald]

Do you have a proxy in front of your container? What OS are you using to run your container?

[SB]

Could webmail login fails be triggering localhost to be blacklisted?

[SH]

Screenshot at https://postimg.cc/MXTSBNxq is self-explaining. In this configuration poste.io will never work. See https://poste.io/doc/network-schemes