Email domain connected to alternate server
We have a sister company transitioning their email activities over to Marketo, but until completed I'd like to send emails to their lead base using their independent email domain.
Marketo shows that we can create unlimited DKIM and SPF configurations, but the sister company's email domain is currently pointing at an ExactTarget namespace server. We still have a need to use ExactTarget until the full transition and workforce training has been complete for Marketo. With that understood, is there any harm to sending from Marketo using an email domain whose reply mail is managed by ExactTarget?