Forward exist email account address

I have create a main address info@mydomain.com and I setup outlook. I want also this address forward to other email (gmail).

I made the following tests:

a)
1. create the mail account info@mydomain.com
2. I set up forwarder for info@mydomain.com to my gmail account

if I sent mail to info@mydomain.com I receive mail in gmail but not in inbox.

b)
1. I set up forwarder for info@mydomain.com to my gmail account
2. create the mail account info@mydomain.com

if I sent mail to info@mydomain.com I receive mail in inbox but not in gmail.

so postfix ignore the first rule always.

Till now I used cpanel and this setup works correctly

Thanks