Enable Web API, e.g. REST API, to be used for your account
This would be especially helpful to integrating and scripting your own tasks should TravelingMailbox.com not support what you're trying to do.
For example, I'd like to create a workflow for my mail that would download (via integration) to my Google Drive, then Hazel (on my Mac) would move the downloaded file elsewhere, and then set a label/tag on the file (on TravelingMailbox.com) (e.g. tag "downloaded").