A method implemented in a fax machine for analyzing a received fax to determine whether it is an auto-reply fax. Auto-reply faxes are handled differently from other faxes to avoid unnecessary printing. The analysis method includes: determining whether the sender of the received fax is the same as the receiver of a fax sent by the fax machine within a predefined time period in the past; determining whether the received fax contains only one or two pages; extracting text from the image of the received fax using OCR; and detecting the presents of certain keywords in the extracted text which indicate an auto-reply or received status. These determination and detection results are combined to determine whether the received fax is an auto-reply. Auto-reply faxes may be saved but not automatically printed, or forwarded to an email box of the sender of the original fax, etc.