"user@domain.com" smtp user style

Hello

How I can to configure virtualmin gpl to use "user@domain.com" user style to send mail ?

I just read this post:

http://www.virtualmin.com/component/option,com_fireboard/Itemid,77/func,view/id,8354/catid,7/

This post say:

"Virtualmin fully supports user@domain.com usernames with Postfix. You just have to turn it on in the Server Template(s) ("Mail for domain section", option is labeled "Format for usernames that include domain") and set the Module Configuration in the "Defaults for new domains" section option labeled "Include domain name in usernames?" to "Always" and the "Domain name style in username" to "Full domain name"."

I have followed these advices but only pop3 user are like "user@domain.com" style, the smtp user still "user.domain.com"

Thanks for any help and thanks to virtualmin team for your work.

roberto