To override the Content-type in your clients, use the HTTP Accept Header, append the .csv suffix or ?format=csv
HTTP + CSV
The following are sample HTTP requests and responses.
The placeholders shown need to be replaced with actual values.
POST /csv/reply/UnsubscribeRequest HTTP/1.1
Host: click.email4customers.com
Content-Type: text/csv
Content-Length: length
{"UserLogin":"String","DestinationEmail":"String","CustomReason":"String","UnsubscribeReasonId":0,"MessageId":"String"}
HTTP/1.1 200 OK
Content-Type: text/csv
Content-Length: length
{}