Edit /etc/postfix/master.cf, and add the following lines:

127.0.0.1:10026     inet  n      -      n      -      10      smtpd -o content_filter=
                       -o receive_override_options=no_unknown_recipient_checks,no_header_body_checks,no_milters
                       -o smtpd_helo_restrictions=
                       -o smtpd_client_restrictions=
                       -o smtpd_sender_restrictions=
                       -o smtpd_recipient_restrictions=permit_mynetworks,reject
                       -o mynetworks=127.0.0.0/8

Edit /etc/postfix/main.cf and add the following lines:

recipient_delimiter = +

content_filter = smtp:[127.0.0.1]:10025

# if you set this, then postfix will give the email address to clapf without
# rewriting it so make sure to set the email aliases to the email table
receive_override_options = no_address_mappings

default_destination_concurrency_limit = 10
smtpd_recipient_limit = 128

lmtp_send_xforward_command = yes
smtp_send_xforward_command = yes
smtpd_authorized_xforward_hosts = 127.0.0.0/8

If you want LMTP local delivery instead of SMTP, then set server_mode=0 in clapf.conf, and use the following content_filter reference:

content_filter = lmtp:[127.0.0.1]:10025

Issue the postfix reload command

postfix reload

Edit the /etc/aliases file to accept spam@ and ham@ addresses as aliases (or you may use virtual aliases too):

 ham: /dev/null
 spam: /dev/null

Then issue the 'newaliases' command.

The clapf daemon can handle a finite number of recipients, 128 by default. If you want more recipients in a single session edit MAX_RCPT_TO in config.h then (re)compile clapf and adjust the smtpd_recipient_limit variable in main.cf. If you want less than 128 you should only adjust the smtpd_recipient_limit variable in main.cf.

Please note that if you want to increase the concurrency, modify the default_destination_concurrency_limit in main.cf, the 127.0.0.1:10026 entry in master.cf and the number_of_worker_processes in clapf.conf, then reload postfix.

The number_of_worker_processe should be greater than default_destination_concurrency_limit:

number_of_worker_processe ›= default_destination_concurrency_limit + 1