We have two email fields in Marketo/Salesforce - Transactional Email and Subscriptions Email. One is used for marketing, one is used for transactional stuff related to a booking. So if we want to send a transactional email, we will need to ensure that the transactional email is in Marketo's "master" email field, and then send to that. If we then want to send a marketing email, we will need to switch the emails out ....and then send. Messy.
So my question is - using the API, could we say "send this email to this person using the email value in this field", when that field isn't the Marketo master one? That would be super useful. And if not, is there another way to do this (besides the obvious of only have one email field )