How to send from diferent mail servers

We are in need to send mails from diferent servers. (Invoices from server A, Shipments from server B) How I can handle that?
If not, how can Tryton can be improved to support that in the future?

It is not possible to configure multiple SMTP servers. You just have to setup a MTA that will transfer each email to the proper next relay.

I do not think we will want to make the email sending any more complex.