PMDF System Manager's Guide

The G3_TO_FAX channel is capable of sending to the originator of the FAX message delivery acknowledgements in the form of e-mail messages. In addition, both the PS_TO_G3 and G3_TO_FAX channel will, when necessary, send error messages (again via e-mail) to the FAX's originator.

By default, the G3_TO_FAX channel only generates acknowledgement messages when transmission errors occur during an otherwise successful FAX transmission. When the G3_TO_FAX channel option ACKNOWLEDGEMENT is set to 0, delivery acknowledgements are sent after a successful FAX delivery regardless of whether or not transmission errors were reported provided that either NOTARY was not used to submit or relay the message to PMDF, or, if NOTARY was used, that delivery reports (DSNs) were requested.⁵

Acknowledgements are preferentially sent to the delivery receipt address specified by a Delivery-receipt-to: header line. If no such header line is specified, then the address specified by a Reply-to: header line is used. Finally, if no Reply-to: header line is present, then the envelope From: address is used. If the originating message specifies a delivery receipt address of <>, then no acknowledgement will be generated. If USE_REPLY_TO=0 has been specified in the G3_TO_FAX channel option file, then the Reply-to address will never be used: if no delivery receipt is specified then the envelope From: address will be used regardless of whether or not a Reply-to: header line is present in the originating message.

When permanent delivery errors (e.g., bad FAX telephone number) occur during FAX delivery or the maximum number of delivery attempts has been exceeded for a particular recipient, the G3_TO_FAX channel sends an e-mail message explaining the problem to the message's originator. Such messages are sent, whenever possible, to the address specified by the Errors-To: header line in the originating message's header. If no such header line is present, then the envelope From: address is used instead.

The PS_TO_G3 channel may also generate e-mail messages which are returned to the FAX message's originator. A list of bad addresses will be returned to either the Errors-To: or envelope From: address should one or more improperly formed addresses (e.g., an AVPL missing a FAX telephone number, an address not in AVPL format, etc.) be encountered in the address list. The FAX message will, however, continue to be processed for any correct addresses which may remain. Should the PS_TO_G3 channel's PostScript interpreter generate output, that output will be returned to either the Reply-To: or envelope From: address along with an explanatory note.

Note that if the PS_TO_G3 channel needs to bounce a FAX message due to some error---and even more so if the G3_TO_FAX channel needs to bounce a message -- by that point the "original" message contents have already undergone a great deal of processing (in particular, attachments may have been deleted or contents converted to PostScript). By default, therefore, PMDF-FAX does not attempt to return message content in bounce messages. However, setting the PS_TO_G3 channel option RETURN_CONTENT=1 and the G3_TO_FAX channel option RETURN_CONTENT=1 tells PMDF-FAX to include the current PostScript version of the message in the bounce message.