Are IPN retries from PayPal supported?

Greetings:

Just finished testing the Fundraising plugin. I did a test before setting up the IPN settings, which is now complete. So my question is, I want the pledge to show up...but will it receive a retry from PayPal from the transaction? Or will that one simply not show up as I did it before setting the IPN up?

I'd like to make sure it all works well before sending it out to people to donate, and want to be certain pledge info is showing up first.

Cheers!