Set the mailname

src/freedombone-base-email

@@ -896,6 +896,8 @@ function install_email {
         chown -R $MY_USERNAME:$MY_USERNAME /home/$MY_USERNAME/Maildir
     fi
 
+    echo "$DEFAULT_DOMAIN_NAME" > /etc/mailname
+
     function_check configure_firewall_for_email
     configure_firewall_for_email
     dpkg-reconfigure --frontend noninteractive exim4-config