Handbook:Advanced Server Configuration:Rejecting Junk Facsimile

By default HylaFAX will accept inbound facsimile from any caller. If the QualifyTSI configuration parameter is setup then HylaFAX will receive inbound facsimile only if the caller sends an acceptable Transmitting Subscriber Identification (TSI) string; a string that uniquely identifies who the sender is. HylaFAX determines which TSI are acceptable by using the rules given in the file specified with QualifyTSI. This mechanism provides a way to automatically reject junk facsimile. Note however that because a TSI is not authenticated in any way it is a simple matter for a caller to masquerade as an acceptable sender and bypass the access control mechanism. Consult tsi(4F) for complete details of this facility.