Troubleshooting

“That is a Sending access key. It can send email but cannot manage domains.” LetterWP needs a Full access key to read your domains and set up your list. In Resend, create a new key with Full access and paste that.

“Resend does not recognise that key.” The key was cut short when you copied it, or it was deleted in Resend. Resend shows a key only once, so create a new one.

Open the domain under LetterWP → Setup → 2. Domains. Each DNS record has its own status. Compare each one with what your DNS host has: type, name and value.

On Cloudflare, set every record to DNS only (grey cloud). A proxied (orange) record makes the check fail.

Then click Check again and reload the page in a minute. DNS can take a few hours to show up.

“Verified, but sending is off in Resend” means sending was turned off for this domain in Resend’s dashboard. Turn it back on there.

Mark the email “Not spam”. Check the domain shows Ready to send, then add a DMARC record if it shows No DMARC: a TXT record named _dmarc with the value v=DMARC1; p=none;. It never blocks anything, and Gmail and Yahoo trust a domain more with one. It can take up to 30 minutes to show as DMARC found.

Send your tests to Gmail: it is the strictest. If the test fails with an error instead, that is Resend’s own message, usually about the domain not being ready.

The switch only works once the site can send. The line under it names what to fix, with a link: “Connect Resend to send posts as email.”, “Set the newsletter email address first.”, “yourdomain.com is not ready to send yet.” or “Run Setup once, so posts have a list to go to.” Fix it, then reload the editor.

On a published post, the switch is locked: editing a published post never sends it again. If it was published without an email, use Email this post… in the same panel. Private posts are never emailed.

The reason follows “Not sent.”:

• “Setup has not run: there is no list to send to.” Click Run setup in LetterWP → Setup → 3. Your list in Resend.
• “This post’s category has no topic at Resend yet.” Run setup again in the same place.
• “Set the newsletter email address in LetterWP → Setup → 4. Sender addresses first.”
• “Password-protected posts are not emailed.” Remove the password if you want to email it.
• A message that starts with “Resend:” is Resend’s own error.

Fix the cause, then click Try again in the panel. Only a failed send can be tried again.

“Resend did not answer (…). It may have sent anyway: check Resend → Broadcasts before trying again.” Or: “The send stopped before Resend answered.”

The request ran out of time, but Resend may still have sent the email. Open Broadcasts in your Resend dashboard. If the post is there and sent, don’t click Try again: readers would get it twice. If it isn’t there, click Try again.

Pending means they haven’t opened their confirmation link yet. It comes from your transactional address, with the subject “Confirm your subscription to” your site name. Ask them to look in spam. The link works for 24 hours. Subscribing again with the form sends a new one.

Pending people are never added to Resend and never get newsletters. If someone asked you directly, open them in Subscribers, click Edit, set Status to Active and click Save changes.

If the form says “This site cannot send email right now. Please try again later.”, Resend isn’t connected or no sender address is set.

They most likely turned that topic off, on your account page or on Resend’s unsubscribe page. The Topics column on Subscribers shows All, the topics they get, or None.

Each email goes out under one topic, picked in the Newsletter panel. A reader who turned that topic off doesn’t get the email, even if they get the post’s other categories. Their choices are on their Edit screen. Change them only if they ask you to.

Results come from Resend’s webhook. Check its row under LetterWP → Setup → 3. Your list in Resend. If it doesn’t say Ready, click Run setup or Run setup again. The “Last event” line under it shows when Resend last reached your site.

Resend must be able to reach your site at the address shown there. A site on your own computer, behind a password, or with its REST API blocked by a security plugin gets no events. Posts sent while the webhook was off show “No results”.

Results take a few minutes after sending. “Waiting for Resend…” is normal at first.

Leaving the page pauses it. Go to Subscribers and click Carry on next to “N imported subscribers are not in Resend yet.”

“Stopped: Resend kept refusing. Check the Resend key in LetterWP → Setup, then try again.” Make sure step 1 still says Connected, then click Try again. “The connection dropped. Try again.” means your browser lost the connection: click Try again.

If you imported before running setup, nobody was sent to Resend. Click Run setup, then Sync to Resend now at the bottom of Subscribers. It adds everyone who is missing.