[Ultimate Branding] Network SMTP + optional SMTP per site

I'm happy to see that SMTP has found its way into the Ultimate Branding plugin. Yet a great improvement, from my perspective, would be to add an option to allow network sites to configure their own SMTP.

This could be useful for many situations, like:
- Sending a newsletter from a sub site.
- Sending order confirmations.
- For sub sites with members.
... To name a few.

Currently, as far as I'm aware, there is no SMTP plugin that allows to set a network default, which can be overwritten on a per site basis. I think it would be a welcome feature.