Summary
A 'no MX' bounce reason signifies that the recipient domain is missing properly configured MX records, essential for directing email to the correct mail server. This absence prevents successful email delivery. Causes include recent domain registration without complete DNS setup, misconfigured DNS settings (incorrect hostname/syntax), temporary DNS server issues, intentional omission of MX records, or simple typos in the recipient's address. While some domains may accept email via A records, this practice is uncommon. Furthermore, a domain being busy or unreachable may return MX server connection errors. Correcting this involves verifying the domain's MX records using online tools, ensuring accurate configuration with proper hostnames and priority, allowing sufficient time for DNS changes to propagate, and seeking clarification from your ESP if problems persist.
Key findings
- MX Record Absence: The primary cause is the lack of a properly configured MX record for the recipient domain.
- DNS Configuration Errors: Incorrect DNS settings, including hostname specifications and syntax errors, contribute to 'no MX' bounces.
- Propagation Delays: Recent DNS changes or new domain registrations may experience delays in DNS propagation.
- Typographical Errors: Mistyped email addresses can also result in 'no MX' bounce messages.
- Unreachable Errors: Domains may be configured correctly, but be unreachable returning an MX connection error.
Key considerations
- Verify MX Records: Before resending, use online tools like `dig` or `nslookup` or websites to check the domain's MX records.
- DNS Configuration: Ensure that MX records are accurately configured with the correct hostnames, priority values, and syntax within the DNS settings.
- Allow Propagation Time: Wait for DNS changes to propagate fully across the internet before assuming the problem is resolved.
- ESP Communication: Contact your email service provider (ESP) to clarify the meaning of the 'no MX' bounce and seek assistance with troubleshooting.
- Check address: Double check the target email address.
What email marketers say
11 marketer opinions
A 'no MX' bounce reason indicates the receiving domain lacks a properly configured MX record, which is essential for directing email. This can result from several factors, including recent domain registration without DNS setup, incorrect hostname or syntax errors in MX record configuration, temporary DNS server issues, or intentional omission of MX records if the domain is not intended to receive email. In some cases, domains may still accept email with just an A record, but this is less common and primarily for legacy reasons. Checking for typos in the recipient's email address and verifying the domain's MX record using online tools are crucial steps in troubleshooting this issue. If issues persist, it is best to contact your ESP.
Key opinions
- Missing MX Record: The domain lacks an MX record, which tells email servers where to deliver mail.
- DNS Issues: Incorrect DNS configuration, recent DNS changes, or DNS propagation delays can cause 'no MX' errors.
- Typographical Errors: Typos in the recipient's email address can lead to a 'no MX' bounce.
- Legacy A Record: Some domains may accept mail via an A record, but this is less common and not best practice.
- Made-up domains: A high volume of no mx errors might indicate fake email addresses.
Key considerations
- Verify MX Records: Use online tools or command-line utilities to verify the recipient domain's MX records before resending.
- Check DNS Settings: Ensure MX records are correctly configured with proper hostnames and priority values.
- Account for Propagation: Allow sufficient time for DNS changes to propagate across the internet.
- Contact ESP: If the issue persists, contact your ESP for further clarification or assistance.
- Check email address: Check for errors and spelling mistakes within the target email address.
Marketer view
Email marketer from SparkPost details that 'no MX' bounces typically indicate a problem with the recipient's domain DNS settings. It suggests the sender verify the domain's MX record using online tools before resending.
1 Mar 2023 - SparkPost
Marketer view
Email marketer from DNSQueries explains that a missing MX record leads to email delivery failures and outlines that this can happen from simple DNS errors, a typo or incorrect record value. If the issue persists, the DNS might not have propagated. Also advises to use their DNS checker to check the record is set up correctly.
30 May 2023 - DNSQueries
What the experts say
2 expert opinions
A 'no MX' bounce indicates that the recipient domain either lacks a mail server configured to receive emails or is experiencing DNS-related issues. While some domains may still be configured to receive emails without an MX record, the absence typically means that emails cannot be routed to the intended recipient. Possible causes include recent domain registration without complete DNS setup, intentional avoidance of email reception, misconfigured DNS settings, or temporary DNS server issues. It is recommended to clarify the error message with your ESP, as wording can be ambiguous, and the underlying issue might be related to the quality or validity of the recipient addresses.
Key opinions
- Missing Configuration: No mail server is configured to receive emails for the given domain.
- DNS Problems: Recent domain registration without proper DNS configuration or temporary DNS issues.
- ESP Clarification: Wording can be misleading when debugging with ESPs, so clarification is important.
- Address quality: If your ESP has flagged it, the email address might be invalid.
Key considerations
- Verify MX Records: Ensure that MX records are properly configured with the correct hostnames and priority settings.
- DNS Propagation: Allow sufficient time for DNS changes to propagate across the internet.
- Clarify with ESP: Ask your email service provider for specifics on the bounce reason and the actions they've taken.
- Investigate Validity: If your ESP gives this bounce, then the target email address may be invalid and should be removed.
Expert view
Expert from Email Geeks points out that domains without an MX record can still accept mail and suggests asking the ESP what they mean when they suppress mail with that error. He also suggests both messages are coming from the ESP, and the wording isn't ideal, advising to ask them to clarify. He adds that they probably mean those addresses are iffy/typoed/bad, but you can't be sure.
13 Jun 2024 - Email Geeks
Expert view
Expert from Word to the Wise explains that a missing MX record means no server is configured to receive mail for that domain. Common causes include recent domain registration where DNS records haven't been properly configured or propagated, or the domain owner simply doesn't want to receive email at that domain. Additionally, incorrect DNS settings or temporary DNS server issues could be the cause.
21 Dec 2024 - Word to the Wise
What the documentation says
4 technical articles
A 'no MX' bounce reason, as indicated by documentation from Google Workspace, RFC 5321, DNSimple, and Cloudflare, signifies that the destination domain lacks properly configured MX records. These records are essential for directing email to the correct mail server, facilitating email message acceptance on behalf of the recipient's domain. Without a properly configured MX record, email delivery will fail, as there is no information on how and where to deliver the messages. A preference value is also set within the DNS settings for trying multiple servers.
Key findings
- Missing MX Record: The recipient domain lacks an MX record, preventing email servers from locating the correct mail server.
- Essential for Routing: MX records are crucial for directing email to the appropriate mail exchanger.
- Delivery Failure: Without an MX record, email delivery will fail, resulting in a bounce.
- Preference values: MX records also define which order to try multiple servers.
Key considerations
- Ensure MX Configuration: Domain owners must configure MX records to enable email reception.
- Utilize Proper Values: Ensure the correct hostnames and priority are set in the DNS settings.
- DNS Verification: Always verify the DNS settings and record values are correctly set to prevent email bounces.
Technical article
Documentation from DNSimple explains that an MX record specifies a mail server responsible for accepting email messages on behalf of a recipient's domain, and a preference value is defined, which determines the order in which mail servers should be tried.
3 Oct 2024 - DNSimple
Technical article
Documentation from RFC 5321 describes that MX records are used to locate the mail exchangers for a domain. If no MX records are found, the address is treated as if it has no mail forwarding capability.
2 Mar 2022 - RFC Editor
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