Is it possible to send email from Exact Target using Custom Object in Salesforce? I tried with Triggered Sends and Send Definition but its always asking for Lead/Contact look up for Email address. In my case I have to send email from custom object having email address as custom field.
I had a similar issue and found this can work using the send to reports with Salesforce email sends / data extensions if a report can be created with the custom object and a Contact or Lead ID associated with the custom object
This was a useful video in helping me configure this