Dovecot silently discards duplicates?

[dovecot at ptld.com]

I setup an alias at example.com in postfix to point at me at example.com

I send one email to me at example.com and alias at example.com, tried both 
ways of using CC and putting both addresses in the To field.

I see in postfix logs that it delivers two messages to dovecot-lmtp.

However i only get one copy of the email in my inbox.

I assume dovecot is detecting duplicate emails going to the same 
location and just discarding one of them.

Is there a setting to control this behavior? Can dovecot be told to 
deliver what it was given and not decide to discard?