I finally came throughout this,it is something like what you say falko.
I also noticed that virtualdomain.tld and others domains weren't listed on what I was getting with postconf-n ,and I also guessed that the messages for likob.bi were well delivered.
In main.cf ,for every virtual domain I would like to host ,I was adding those lines:
I changed this way by adding only these 2 lines:
and I created the file /etc/postfix/virtual_alias_domains
which is in this format (domain date) ,the date is not necessary.
Don't forget postmap hash:/etc/postfix/virtual_alias_domains and of course the postfix reload.
And it worked
,so from now on, every virtual domain I want to host I only add it in /etc/ postfix/virtual_alias_domains and I make the mappings in /etc/postfix/virtual ,followed with postmap.