ISPManager 5 - Child process of dovecot deliver pipe transport returned 75 (could mean temporary error)

Dovecot не принимает письма с ошибкой в логах:

2017-08-29 20:16:55 1dmk8D-0007yx-Oi == [email protected] R=procmail T=dovecot_deliver_pipe defer (0): Child process of dovecot_deliver_pipe transport returned 75 (could mean temporary error) from command: /usr/libexec/dovecot/dovecot-lda

Помог - простой перезапуск dovecot:

# :> /var/log/dovecot.err
# systemctl restart dovecot