Thought I'd inquire here before waiting on hold for Godaddy "support". I started receiving these emails a few days ago. They seem to be generated with every sale at my site. I haven't made any changes to the site in months. Any ideas or direction would be much appreciated. Her's the text of the emails:

Please check your server that handles PayPal Instant Payment Notifications (IPN). IPNs sent to the following URL(s) are failing:

https://www.perfectpetfeeder.com/store/vsadmin/ppconfirm.php

If you do not recognize this URL, you may be using a service provider that is using IPN on your behalf. Please contact your service provider with the above information. If this problem continues, IPNs may be disabled for your account.

Thank you for your prompt attention to this issue.
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Thanks, Scott

Hi Scott

We are seeing a few of these reports from Godaddy users - it is something they can fix for you - have a look at the final posts on the thread here https://www.ecommercetemplates.com/support/topic.asp?TOPIC_ID=108969&whichpage=2

Andy

Please feel free to review / rate our software

Thanks Andy,

I contacted GoDaddy to learn that my site had been hacked a while back and that may be the problem. I've had them clean the site of malware and set up a firewall, for a price, of course. Hopping that resolves the issue.