[Exim] Exim and accounting

Hi all,

Does anybody have any advice on the best way we can reliably collect accounting
information for delivery to certain hosts/domains? We are looking at launching
an email to SMS gateway service for our customers. This has already been
easily achieved using an SMTP gateway and sieve rules. The only problem is
that we need to on-bill the cost of each txt message (i.e. each successful SMTP
delivery to sms.domain.com) back to the customer.

I realise this information can be extracted by parsing the logs with some custom
shell/perl scripts, but I don't want to reinvent the wheel... Ideally we would
like to update a MySQL database with an insert statement for each successful
delivery to the sms domain. If log files are the only way to go then is it
possible to log deliveries in a customised format to a separate log file for a
given domain?

Cheers,
Ray