Mail sent thru submission to user on same server.

[postfix]

If i send mail to submission:587 addressed to another user on the same 
server, postfix instead of sending the mail to the mx records for that 
domain, and connecting to postfix on smtp:25 it bypasses all of that and 
delivers directly into that users inbox. This avoids all of my 
filtering, smtpd_helo_restrictions, smtpd_recipient_restrictions, ban 
list, etc.

I am hoping for an answer that works in both of these situations. I have 
two setups, one where everything is self contained on one server with 
dovecot and postfix.

On my second setup i have postfix smtp:25 on one server, and dovecot 
imap:143 with postfix submission:587 together on another server. I want 
when someone sends an email from their client to the submission server, 
the submission server would connect to the smtp:25 server to deliver the 
mail. But the submission:587 server directly delivered to the user's 
folder and bypassed the smtp:25 server.

How can i avoid this behavior and make postfix deliver the mail to "the 
front door" smtp:25 even if its a user on the same system?