Thunderbird connection error

What type of hardware are you using

Other ARM board

What YunoHost version are you running

11.2.31

How are you able to access your server

The webadmin
SSH
Direct access via physical keyboard/screen

Are you in a special context or did you perform specific tweaking on your YunoHost instance ?

yes

Describe your issue

Hi,

I’ve configured a catchall on my server to receive all emails sent to my domain in a single user’s inbox, and it’s working well. After three years of procrastination, I’ve finally set up a Sieve filter to create a folder for each “to” address.

/* Create folder for all other emails */

if address :localpart :matches ["to"] "*" {
    # Store the local part of the "To" address in a variable
    set :lower :upperfirst "localpart" "${1}";

    # Use the local part to create the folder name
    fileinto :create "INBOX.${localpart}";
    stop;
}

The filter works well, but in Thunderbird, I regularly see the following error:

Le serveur *** s'est déconnecté. Il s'est peut être arrêté, ou il y a un problème sur le réseau.

On the server side, I see these logs:

Oct 28 12:07:24 *** dovecot[2758744]: imap-login: Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10): user=<***>, method=PLAIN, rip=***6, lip=***, TLS, session=<***>
Oct 28 12:07:25 *** dovecot[2758744]: imap-login: Maximum number of connections from user+IP exceeded (mail_max_userip_connections=10): user=<***>, method=PLAIN, rip=***, lip=***, TLS, session=<***>

I don’t experience this issue on K-9 Mail.

In Thunderbird, I tried adjusting the setting Nombre maximum de connexion à garder en cache to 1 (though I’m unsure of its effect).

Is there a way to increase mail_max_userip_connections? I’m not certain where to change this setting.
Or is there anything else I can change to avoid thunderbird errors?

Thank you for your help! :grinning: