Hi, this is my configuration # OS: Linux 2.6.32-131.0.15.el6.x86_64 x86_64 Red Hat Enterprise Linux Server release 6.1 (Santiago) ext4 auth_debug = yes auth_master_user_separator = * auth_username_format = %Lu auth_verbose = yes disable_plaintext_auth = no info_log_path = /var/log/dovecot-info.log log_path = /var/log/dovecot.log log_timestamp = "%Y-%m-%d %H:%M:%S " login_greeting = Dovecot ready mail_debug = yes mail_gid = 999 mail_home = /MAIL/%d/%n/ mail_location = maildir:/MAIL/%d/%n/ mail_log_prefix = "%Us(%u): " mail_plugins = " quota" mail_privileged_group = mail mail_uid = 999 passdb { args = /etc/dovecot/dovecot-ldap.conf driver = ldap } passdb { args = /etc/dovecot/passwd.masterusers driver = passwd-file master = yes pass = yes } plugin { quota = maildir:User quota quota_warning = storage=95%% quota-warning 95 %u quota_warning2 = storage=80%% quota-warning 80 %u sieve = ~/sieve/dovecot.sieve sieve_dir = ~/sieve } protocols = imap pop3 sieve service auth { unix_listener auth-userdb { group = mail mode = 0660 user = postfix } } service managesieve-login { executable = /usr/libexec/dovecot/managesieve-login inet_listener sieve { port = 4190 } } service quota-warning { executable = script /usr/local/bin/quota-warning.sh unix_listener quota-warning { group = mail mode = 0666 user = mail } user = mail } ssl = no userdb { args = /etc/dovecot/dovecot-ldap.user driver = ldap } doveconf: Error: protocols: Unknown protocol: sieve doveconf: Fatal: Error in configuration file /etc/dovecot/dovecot.conf: protocols: Unknown protocol: sieve I get the error Unknown protocol: sieve The installed rpm package is this: dovecot-2.0.9-2.el6.x86_64 The sieve filtering is working: 2011-12-07 12:12:29 LDA(utente01@***): Debug: sieve: opening script /MAIL/***/user//sieve/dovecot.sieve 2011-12-07 12:12:29 LDA(utente01@***): Debug: sieve: script /MAIL/***/user//sieve/dovecot.sieve successfully compiled 2011-12-07 12:12:29 LDA(utente01@***): Debug: sieve: executing script from /MAIL/***/utente01//sieve/dovecot.sieve 2011-12-07 12:12:29 LDA(utente01@***): Info: sieve: msgid=<4EDF4A1C.9010509@***>: stored mail into mailbox 'INBOX' But the manage sieve won't work. It seems that pigeonhole is installed because /usr/libexec/dovecot/managesieve-login exist and is not empty. Can you help me? Thank You Sushi.