Logging spandsp

Hello everybody :smile:
I currently am running a server with asterisk 1.2.4 svn and spandsp 0.0.2pre5 installed and everything works fine. my machine is connected to a E1 PRI through a TE110P Digum card and I am planning to use this machine for a fax2mail - mail2fax service. I wrote myself a script to handle this type of service but would like to be able to know if the faxes sent by TXFAX went through ok or no so that I can send a confirmation email or a failure to the user. I believe it is possible to do since there are scripts around (Like asterfax) that can send this kind of receipts… So how do I “log” fax successes from txfax?
By the way, I place my fax calls by creating a xxxx.call file that I place in /var/spool/asterisk/outgoing.

Thanks in advance for your replies