We're using Extole for our referral marketing platform, and we need to transer our do not send list to this system. Is there any way we can do this via SFTP?
Alexis, No - this is not supported today. A shameless plug - please consider using the Marketo referral app instead of extole. The Marketo referral app is tightly integrated into Marketo assets, smart campaigns, activity log, etc.
This perhaps doesn't answer your question regarding using SFTP, but can't you just export the list from your smart list as a CSV or whatever file format and import to the application you're using? That's what I do all the time.