Just as you can formward incoming faxes to you eMail account, you can send a transmission confirmation when a facsimile was sent successfully. You can even send a copy of the fax along with it.
bin/notify is the command script invoked by the facsimile server to notify a user about the status of an outbound job. It parses etc/FaxNotify so you can customize the script by editing the parameter file.
Unfortunately the variable names are quite different from the bin/faxrcvd script. To send a pdf copy of you outgoing facsimiles to you eMail address you have to change FaxNotify as follows:
RETURNFILETYPE=pdf; mailaddr=user@domain.tld;
The allowed values for the RETURNFILETYPE variable are just the same as for FILETYPE in the bin/faxrcvd script: ps, tif or pdf.
And you can of course alter the bin/notify script itself, too. But as bin/faxrcvd it is part of the package distribution and subject to being overwritten by subsequent upgrades.