Resend MX verification fails: your DNS provider appends your domain name

TL;DR

If you see your own domain glued on the end (e.g. feedback-smtp.eu-west-1.amazonses.com.example.com instead of feedback-smtp.eu-west-1.amazonses.com), your provider auto-appends the domain name.

Steps

1. Symptom: the MX record looks right in your provider's panel but Resend keeps failing it.
2. Confirm the cause: check the actual public value with nslookup -type=MX on the send subdomain. If you see your own domain glued on the end (e.g. feedback-smtp.eu-west-1.amazonses.com.example.com instead of feedback-smtp.eu-west-1.amazonses.com), your provider auto-appends the domain name.
3. Fix: in your DNS provider, edit the MX value to end with a trailing period, e.g. feedback-smtp.eu-west-1.amazonses.com. with the dot. The trailing period marks it as a fully qualified domain name that must not be modified.
4. The region in the MX value matters: it may be us-east-1, eu-west-1, ap-northeast-1, or sa-east-1 depending on your domain's region. Copy the exact value from your domain's DNS records table.
5. The same trailing-period trick applies to CNAME values when the provider shows the Resend host with your domain appended.
6. Verify: re-run the nslookup and confirm the public value now matches Resend exactly, then hit "Restart verification" in the dashboard.

When to use

You are seeing this: Symptom: the MX record looks right in your provider's panel but Resend keeps failing it. Use this skill when you run into "Resend MX verification fails: your DNS provider appends your domain name".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.

Documented in Resend knowledge base: some DNS providers append the domain to MX values; the fix is a trailing period making it a fully qualified name; the MX region (us-east-1, eu-west-1, ap-northeast-1, sa-east-1) must match the domain's region; same applies to CNAME values. Evidence: resend.com/docs/knowledge-base/what-if-my-domain-is-not-verifying.