====== Dovecot 2.3 IMAP high-performance mode ======

=== Default configuration ===

This is the default Debian 12 Bookworm configuration for Dovecot 2.3:

<code>
default_process_limit = 100
default_client_limit = 1000
service imap-login {
  client_limit = 0
  process_limit = 0
  process_min_avail = 0
  service_count = 1
}
</code>

After increasing the **default_process_limit = 400** you can still face the following warning log message:

<code>
dovecot: master: Warning: service(imap-login): process_limit (400) reached,
    client connections are being dropped
</code>

This is because the **service_count = 1** limits each imap-login process to handle only one login request. This configuration is very high in security, but very inefficient.

=== High performance configuration ===

Removing the limit with **service_count = 0** you can set some limits specifically for the imap-login:

<code>
service imap-login {
    # 16 processi × 500 client = 8000
    service_count = 0
    process_min_avail = 8
    process_limit = 16
    client_limit = 500
}
</code>

With **process_min_avail** you can set how many processes are always ready to answer login requests, the **process_limit** is set to the number of available CPUs.

==== Comandi per debug ====

Mostra la configurazione di Docevot, solo i parametri diversi dal default:

<code>
doveconf -n
</code>

Alcune statistiche di funzionamento dei vari servizi:

<code>
doveadm service status imap
doveadm service status imap-login
doveadm who
</code>