I am pretty sure EPDM does not track/store dynamic notifications. I suppose you could go through your Exchange log files in a pinch, but that wouldn't be very easy.
I found a blog entry that I wrote back in 2008 On the fly email notifications - 3DVision Blog I wrote it before dynamic notifications existed but it may have value in this case? You could at least include yourself in the Cc: list to know who got the notification.
We have an add-in for EPDM available that allows you to send emails to specific users based on datacard values:
It also logs notifications if you need an audit trail.