error trying to add feed

I can't see any problem with the feed; the image is the correct dimensions and filesize, the episode file plays in a browser as it should, the feed can be subscribed to in iTunes and the server appears to handle byte range requests as required for iPhone. The content issues which can get some podcasts rejected wouldn't seem to apply to yours.

However the complaints that the connection was reset suggests the server is not reacting properly to requests specifically from the Store - we've seen other cases where this might be an explanation though I've never seen a confirmation that this can actually happen. You could ask the people running your server whether there are any logs which might clarify this.

It's also possibly that the Store is simply having a hissy fit - this is not unknown - so if you left it a couple of days and tried again it might work (or it might not).

There is no email contact for Support. If you want to try that route go to https://itunespodcasts.zendesk.com/hc/en-us/requests/new and click the disclosure triangle at the right of the 'Choose a topic' field - choose 'Submission Inquiry' and proceed from there. I can't promise you will get a helpful answer.