What does SMTP Bounce Reason 4.1.8 (bad sender's system address) Domain of sender address does not resolve mean?

Email marketer from SparkPost shares that a 4.1.8 status code often indicates a transient DNS failure and retries are recommended, but may require more urgent attention if it doesn't resolve quickly.

Email marketer from Postmark shares that while less common, 4.1.8 errors *could* potentially be related to DKIM issues if the recipient server is particularly strict. They recommend verifying the DKIM signature for outbound emails.

Email marketer from EmailOnAcid shares that a 4.1.8 error might also arise if the sender's domain has a poor reputation. Some recipient servers might reject emails from domains with a history of spam or abuse, leading to this type of bounce.

Email marketer from Litmus shares that, when encountering a 4.1.8 error, it is vital to ensure the sending domain is correctly configured in the DNS settings, including proper A, MX, and SPF records.

Email marketer from EmailAdmin Forum responds that if DNS records have recently been updated, propagation delays might cause temporary 4.1.8 errors. They suggest waiting 24-48 hours for the DNS changes to fully propagate before investigating further.

Email marketer from StackOverflow answers that the 4.1.8 error is often related to SPF record issues. They suggest checking your SPF record to ensure it is correctly configured to authorize your sending server.

Email marketer from Mailjet shares that a 4.1.8 bounce code suggests the receiving server couldn't resolve the sender's domain. This can be a temporary DNS issue, but if it persists, it could indicate a problem with the sender's DNS configuration.

Email marketer from Reddit explains that a 4.1.8 error often points to DNS problems on the sender's end. They advise checking the DNS records, specifically the A and MX records, to ensure they are correctly set up and resolving properly.

Email marketer from Gmass shares that bounce code 4.1.8 can be triggered when the recipient's email server determines that the sender's domain has an invalid address and cannot be resolved.

Expert from SpamResource explains that a 4.1.8 bounce often indicates that the receiving server could not resolve the sender's domain name. This is frequently caused by DNS configuration problems or a temporary outage.

Expert from Email Geeks explains that 4xx is a deferral, not a bounce, and is a very normal response to transient DNS failures. Deliveries will be retried and can be ignored unless escalated to a rejection after a number of deferrals.

Expert from Word to the Wise shares that a 4.1.8 error can be triggered when the sender's domain has reputation issues, or the system address is not resolving. This could be caused by DNS configuration problems or a temporary outage.

Documentation from RFC Editor details that 4.1.8 enhanced status code indicates a 'bad sender's system address'. The domain name does not resolve, or the address is syntactically incorrect. (this is a permanent error).

Documentation from Microsoft Docs explains that SMTP error code 4.1.8 indicates a problem with the sender's domain name resolution. It usually means the recipient's mail server was unable to resolve the sender's domain, which could be due to DNS issues or a misconfigured domain.

Documentation from Google explains that bounce messages with a 4.1.8 error can occur when the recipient server cannot resolve the sender's domain. This might be due to DNS misconfigurations or temporary DNS server issues. Suggests checking domain configuration.

Documentation from AWS explains that with regards to SES, a 4.1.8 error means the recipient's mail server could not resolve the domain name of the address in the Return-Path header. Check that the domain's DNS records are correctly configured and publicly accessible.