about outgoing mails

I use taps file on qmail in order to send to a mail adress all outgoing 
mails from indivual mail adress as below;
cat /var/qmail/control/taps

[email protected]:[email protected]

it works. but there is a problem. when the [email protected] send a mail to 
[email protected] ,  the [email protected] receives two mails.

How can I get rid of that ?
could you give me an example?

Thanks 


!DSPAM:4c782b6f32711625312960!