Proxy Settings

See Proxy PasswordDatabase for more details.

login_trusted_networks = 10.0.0.0/8

Include Dovecot Proxy’s IP addresses/network so they can pass through the session ID and the client’s original IP address. If Open-Xchange is connecting to Dovecot Directors, it’s also useful to provide OX’s IPs/network here for passing through its session ID and the web browser’s original IP address.

lmtp_proxy = yes

Enable LMTP to do proxying by doing passdb lookups (instead of only userdb lookups).

login_proxy_max_disconnect_delay = 30 secs

New in version v2.2.19.

This setting is used to avoid load spikes caused by reconnecting clients after a backend server has died or been restarted. Instead of disconnecting all the clients at the same time, the disconnections are spread over longer time period.

#doveadm_password =

This configures the doveadm server’s password. It can be used to access users’ mailboxes and do various other things, so it should be kept secret.

doveadm_port = 24245
service doveadm {
 inet_listener {
     port = 24245
 }
}

These settings configure the doveadm port when acting as doveadm client and doveadm server.

service lmtp {
 inet_listener lmtp {
     port = 24
 }
}

This setting configures the LMTP port to use.

service imap-login {
 service_count = 0
 client_limit = 10000
 process_min_avail = 4
 process_limit = 4
}

These 3 settings configure the imap-login process to be in “high performance mode” as explained in http://wiki2.dovecot.org/LoginProcess. The 4 should be changed to the number of CPU cores on the server.

The client_limit setting should be increased to be as high as needed. The max number of connections per server is client_limit * process_limit, so 40k connections in the above configuration.

service pop3-login {
 service_count = 0
 client_limit = 10000
 process_min_avail = 4
 process_limit = 4
}

Enable high performance mode for POP3 as well (as explained above).