Cherry-pick update (2026): continue using content-filter
Also, SpamAssassin should be nearly-stateless and easy to install, so I should really just run it on xidi.
# After-filter SMTP server. Receive mail from the content filter
# on localhost port 10026.
#
-smtp inet n - y - 5 smtpd
- -o content_filter=smtp:127.0.0.1:10025
+smtp inet n - y - 15 smtpd
+ -o content_filter=smtp:127.0.0.1:10026
-o smtpd_client_connection_count_limit=15
127.0.0.1:10026 inet n - n - - smtpd
-o smtpd_authorized_xforward_hosts=127.0.0.0/8