rationale for /var/spool/mqueue permissions with 5.1R

[Ed Budd]

Hi,

I've been working my way through the sendmail "bat" book (not
*ALWAYS* the most exciting read but informative nonetheless) and
have come across a recommendation to ensure that /var/spool/mqueue is
set as root-owned with mode of 0700. 

However, it appears that by default the permissions on 5.1R are thus (at
least on my two boxes):

root:daemon 
drwxr-xr-x

My question is: why are these permissions set this way or, perhaps more
to the point, what (if anything) am I likely to break if I change them
to the recommendations in the book?

Thanks in advance for whatever insight any of you can provide.

EB