What is your objective?
If your objective is to receive a VoxCommando notification when the camera motion detector records video (or puts photos) in a folder, you do not need to use IFTTT.
In this case, you can have your Watcher generate an event when a new camera file is created at D:\Dropbox\alarm, and that event can trigger a command in VoxCommando. (Of course, the camera footage needs to be saved to that folder.)
If you don't need to see the camera footage but only want to generate an event in VC, you can also have the Watcher automatically delete the file after it is created.
You only need to use IFTTT if you instead want to have your camera send email notifications for some reason. In that case, you need to change the settings on your camera so that it is sending the email notification to IFTTT.
Send IFTTT an email at trigger@recipe.ifttt.com with a hashtag in the subject (e.g. #IFTTT, or #VC, or whatever you have specified in your Applet), and this will trigger the IFTTT Applet that has the same "tag".
It's been a long time since I set up my IFTTT, but I think that you will have to set up the email service in IFTTT to be associated with the same email address that you have used in the camera's SMTP settings.
IFTTT reads messages sent from your email account. Based on the subject line, it will execute the appropriate Applet/recipe.