CF7 “Failed to send your message” with From using my domain

I just took over the maintenance of my brother’s website from the original developer and upgraded to PHP 7.1, WordPress 5.2.1 running Laurel Child Theme, and Contact Form 7 v5.1.3. The original developer had From = “[your-name] <[email protected]>”. I saw that that From field was giving a “!(configuration error) Sender email address does not belong to the site domain.”

When I replaced that wordpress email address with the same one in my To field (“info@” and our domain), it gave me a red “Failed to send your message. Please try later or contact the administrator by another method.” error when I tried a test on the Contact page. I also tried From = “noreply@” (and our domain), per the suggestion at https://blog.cf7skins.com/contact-form-7-email-issues, but that didn’t work either (and neither did “[your-name] noreply@” and our domain). It doesn’t matter what browser I use on my Mac (High Sierra). But when I put From = “[your-name] <[email protected]>” back, it worked–the email was sent, but I of course get the configuration error in the plugin.

Note that I have NOT created a “wordpress@” (and our domain) address on my host yet per the FAQ page, https://contactform7.com/best-practice-to-set-up-mail/, and used that instead. But somehow I doubt that would work either. Something else weird is going on, no?

Any help would be appreciated.

Thank you,
Gary

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