KnowledgePower

Here is the official (not that helpful) explanation of this ‘feature’ from the plugin authors:
http://contactform7.com/configuration-errors/

What it seems to want versus my previous setups is:
a) the from field has to be an email address that is the same domain as the WP installation; set the Reply-To using the email address submitted through the form, i.e.
Reply-To: [your-email]

b) If you are using Subject = [your-subject]
then it expects you to make the
[text* your-subject]
mandatory in the form using that *

Hi Michael,

I arrived here wondering about the same thing.

Here are my GUESSES

1. Having the GA tracking twice on pages (once from Yoast, once from Cloudflare) probably is not good practice but probably doesn’t matter and won’t get double counted.

Related Google help page:
Multiple tracking codes on web pages
https://support.google.com/analytics/answer/1032400

2. … But it does sound like the old pre-universal-analytics code could double count.
see “Using multiple instances of the Classic Google Analytics tracking snippets” on this page https://support.google.com/analytics/answer/1009683

3. The advantage of the Cloudflare route seems to be that you can track everything in one fell swoop even if it is not well implemented yet on a site, or the site has some custom pages (e.g. non WordPress in this example)

4. The disadvantage aside from the not-best-practice double code inclusion would seem to be that your tracking working is then dependent on Cloudflare, which in a way is not “correct” as you should be able to switch off (bypass or abandon) such a CDN at will without it affecting what you are materially doing with the site.

Based on this 4th reflection, I am switching it OFF in Cloudflare and manually going to ensure (from sitemap) that there aren’t pages which Yoast/WP cannot reach.