Question regarding smuggling protection in main.cf

[myfirstnameispaul]

I was just noticing that main.cf is configured for SMTP smuggling protection with this line:

smtpd_forbid_bare_newline = normalize

The Long-term fix provided by the Postfix documentation states to use:

smtpd_forbid_bare_newline = normalize
smtpd_forbid_bare_newline_exclusions = $mynetworks

I was just wondering why the exclusion was left out?

https://www.postfix.org/smtp-smuggling.html

[kiekerjan]

Perhaps the advice changed after we did the changes to mail-in-a-box? Also, it looks to me like the default is smtpd_forbid_bare_newline_exclusions = $mynetworks if it is not set.