Cpanel - roundcube - Error master(imap) read() failed: Remote closed connection (destination service process limit reached)

Ошибка в логах

 tail -n100000 /var/log/mail.err
Oct 10 09:13:58 89-163-135-124 dovecot: imap-login: Error: master(imap): read() failed: Remote closed connection (destination service { process_limit } reached?) (client-pid=3129516, client-id=67107, rip=::1, created 1093 msecs ago, received 0/4 bytes)

решение - поднять лимиты в WHM --> Mailserver Configuration:

Maximum IMAP Connections Per IP Address
Maximum POP3 Connections per IP Address
до
100