Hi @Zoltan_Polyak ,
Unfortunately, this cannot be possible with NS v7.
Generally, NS is not designed to do this.
The only way is to create alias domains but I don’t think this is what you want.
There are many topics in this Forum regarding this approach of NS. There are some guys who want this, including me.
However, I did this on NS 6.8 as workaround (E-mails got send from wrong maildomain)
Kind regards,
Gabriel