curl -H "Content-Type: application/xml" -H "X-TAXII-Accept: urn:taxii.mitre.org:message:xml:1.1" -H "X-TAXII-Content-Type: urn:taxii.mitre.org:message:xml:1.1" -X POST -d "@post.data" hailataxii.com/taxii-data
And the XML query (assuming you know the collection_name):