Can't Change message size limit in postfix?

postconf -d | grep message_size_limit

Shows:

message_size_limit = 10240000

This limit was not set in /etc/postfix/main.cf so I assume its a default?

I added message_size_limit = 31457280 to my /etc/postfix/main.cf and restarted postfix. But I still get message_size_limit = 10240000 from postconf -d | grep message_size_limit. It's not accepting my change. why?


From the man postconf:

-d    Print default parameter settings instead of actual settings.

You have do not use -d parameter in the invocation of postconf utility.