Good news: Queryfeed now produces W3C-valid RSS feeds. That means you are welcome to use them with IFTTT service!
Here is a screenshot from the IFTTT dashboard. It shows an applet that reads a feed from Queryfeed and sends me emails:
Image may be NSFW.
Clik here to view.
And here what I’ve got in my inbox:
Image may be NSFW.
Clik here to view.
I hope you’ll enjoy the feature.
Thanks,
Ivan.