forwarding aliases don't work with multiple destinations

Hello,

I've configured postfix with username format: user@domain

When I create mail alias with options "Forward to address.." and place one email address in field below it works fine.

But when i place multiple email addresses in "forward to address" field, so forward is not provided by /etc/postfix/virtual, but /etc/aliases(which not translating it to format -) and when i try to send mail to this alias i receive error:

user1@domain.com (expanded from alias@domain.com): unknown user: "user1"

user2@domain.com (expanded from alias@domain.com): unknown user: "user2"

line created in /etc/aliases:

alias-domain.com: user1@domain.com,user2@domain.com

when i translate this line to:

alias-domain.com: user1-domain.com,user2-domain.com

all works fine.

could You fix it please?