[KenAdam]

I'm a new user having just got a Kindle for Christmas, so please don't shoot me if I've missed something obvious!

Last week, I installed Calibre and set up a couple of news feeds to download at 7am each day, and this worked until Sunday, (when I installed version 0.7.36, and subsequently 0.7.37).
Now, although the news feeds get processed Ok and appear in Calibre, they do not get to the Kindle via my "free" kindle address (no emails from Amazon to say they have been processed either).
If I send them manually via Connect/Share -> email, they arrive as expected.

Auto-send is checked in "sharing books by email".

I'm using my own mail server to send from a dedicated account, and obviously "test email" works (as I can send manually).

I tried setting up another couple of feeds, but they don't download either.

Is there anything else I should check?

Thanks for your help.
Ken