If the domain name of the specified email address has a DMARC or SPF record that would reject the email, Website Toolbox will automatically ignore the Outgoing Email Address setting and will send the email from noresponse@websitetoolbox.com. That address is a shared sender none of your domain's reputation stands behind, so those emails are much more likely to land in spam folders or be filtered away without a bounce. You resolve the issue by authorizing your domain to send email.

Fixing it

1. Open the email authorization setup page. It walks you through each record with instructions for common providers such as Microsoft 365, Cloudflare, and GoDaddy. You can also reach it from Notifications Settings by clicking Connect your email, then Start setup.
2. If your domain already has a DMARC record and no sender has been authorized yet, publish a monitor-only policy of v=DMARC1; p=none at _dmarc.YOURDOMAIN.com while you complete the setup. p=none reports alignment without blocking, so nothing is rejected while you work. Do not delete your DMARC or SPF records. Deleting them removes the protection that keeps your domain's email trustworthy, and it makes deliverability worse rather than better.
3. Complete the SPF and DKIM steps so that your domain is authorized to send. Connect your email explains what each record is and why it matters.

Verifying the fix

Authorization is complete when the Notifications Settings page shows a green check mark next to SPF, DKIM, and DMARC. It can take up to an hour for Website Toolbox to detect a DNS change, so check again after making the changes. Then send a test notification and confirm in your email history that the email went out from an address on your own domain rather than from noresponse@websitetoolbox.com.

If members still report missing email after those checks, follow Why isn't a member receiving our forum emails? (debugging guide).

Note that if the sender and recipient of the email are both the same email address and DKIM hasn't been set up, we will send the email as noresponse@websitetoolbox.com to avoid it being marked as spam by the email provider.

If you are using a free email provider (like gmail.com) for your Outgoing Email address, it will not be possible to make the necessary changes because they do not give you access to their DNS records.