header_checks vs. content_filter?

[Ville Walveranta]

A quick question:

If I have..

content_filter = scan:[127.0.0.1]:10025

in main.cf (plus the corresponding 'scan' entry in master.cf), and..

192.168.1.97:25  inet n -       n       -       -       smtpd
   -o smtpd_client_restrictions=${smtpd_client_restrictions_spamfilter}
   -o
smtpd_recipient_restrictions=${smtpd_recipient_restrictions_spamfilter}
   -o cleanup_service_name=cleanup_service
.
.
.
cleanup_service unix n -      n       -       0       cleanup
   -o
header_checks=pcre:/usr/local/etc/postfix/tables/scrub_passthru_headers.pcre

..in master.cf, which is executed first, the content_filter or the
cleanup_service?

Thanks,

Ville