Quarantine clean emails sent from/to certain local user

Update Amavisd config file, ask it to listen on one additional network port 10030 (you're free to use another port), and one additional policy_bank:

$inet_socket_port = [10024, 9998, 10030];

$interface_policy{'10030'} = 'QUARANTINE';
$policy_bank{'QUARANTINE'} = {
    clean_quarantine_method => 'sql:',
    final_destiny_maps_by_ccat => {CC_CLEAN, D_DISCARD},
};

$clean_quarantine_to = 'clean-quarantine';

Restart Amavisd service.

Append below content to Postfix config file /etc/postfix/master.cf, ask Postfix to listen on one additional network port 10026 (you're free to use another port):

127.0.0.1:10026 inet n  -   -   -   -  smtpd
    -o content_filter=smtp-amavis:[127.0.0.1]:10030
    -o recipient_bcc_maps=
    -o sender_bcc_maps=
    -o mynetworks_style=host
    -o mynetworks=127.0.0.0/8
    -o local_recipient_maps=
    -o relay_recipient_maps=
    -o strict_rfc821_envelopes=yes
    -o smtp_tls_security_level=none
    -o smtpd_tls_security_level=none
    -o smtpd_restriction_classes=
    -o smtpd_delay_reject=no
    -o smtpd_client_restrictions=permit_mynetworks,reject
    -o smtpd_helo_restrictions=
    -o smtpd_sender_restrictions=
    -o smtpd_recipient_restrictions=permit_mynetworks,reject
    -o smtpd_end_of_data_restrictions=
    -o smtpd_error_sleep_time=0
    -o smtpd_soft_error_limit=1001
    -o smtpd_hard_error_limit=1000
    -o smtpd_client_connection_count_limit=0
    -o smtpd_client_connection_rate_limit=0
    -o receive_override_options=no_header_body_checks,no_unknown_recipient_checks,no_address_mappings

Restart Postfix service.

service postfix restart

To quarantine all emails sent from/to user@domain.com, set its per-user transport to smtp:[127.0.0.1]:10026.

Now all emails sent from/to user@domain.com will be quarantined into SQL database (specified in Amavisd config file, parameter @storage_sql_dsn).

Send an email to user@domain.com for testing:

# echo "mail body" | mail -s "test subject" user@domain.com

Quarantine clean emails sent from/to certain local user

See also