We've found spandsp to be quite reliable and robust in recent months, particularly 0.0.3 versions. We have had issues with particular fax machines though. Has anyone else had experiences where some fax machines get errors sending to spandsp and spandsp get's Unexpected DCN sending to some fax machines? Steve, is there a any sort of compatibility list? I really want to establish that there is nothing more I can do outside of spandsp. Cheers, Warrick