Error: Could not send your email. Please try again. When using MailChannels Plugin

I am doing a project in Astro and cloudflare pages. ANd atttempting to use the MailChannels Coludflare plugin. I have followed these instructions (MailChannels · Cloudflare Pages docs) but get this Response on form submission:
Could not send your email. Please try again.
I have looked at many posts and have this code in _middleware.ts:
import mailChannelsPlugin from “@cloudflare/pages-plugin-mailchannels”;

export const onRequest: PagesFunction = mailChannelsPlugin({
personalizations: [
{
to: [{ name: “Some User”, email: “[email protected]” }],
},
],
from: {
name: “Xeffen25”,
// The domain of your from address must be the same as the domain you set up MailChannels Domain Lockdown for (detailed below)
email: “[email protected]”,
},
respondWith: () => {
return new Response(
Thank you for submitting your enquiry. A member of the team will be in touch shortly.
);
},
});
And these DNS records:

Any suggestions??

This is sadly not a direct solution to your issue, but I would recommend avoiding MailChannels and using some other service like Amazon SES, Sendgrid, Postmark, etc.

There are a lot of security implications and their responses to the situation have been very undesirable. Further reading:

To this day, that have still not truly acknowledged the problems, and brushed it aside or “patched” it with paywalls.