SOA Serial Number Format Is Invalid

One factor ensuring smooth email delivery is the DNS (Domain Name System) setup, specifically the SOA (Start of Authority) record. The SOA record is like the starting point for your domain's DNS information. It holds essential details such as which server is the master for your domain, contact details for the domain administrator, and importantly, the serial number, which tells other servers when your DNS records have been updated.

Common misconfigurations in the SOA record can lead to issues in DNS replication and email delivery. One such misconfiguration is an invalid serial number format.

The serial number in the SOA record is crucial because it signals to other DNS servers around the world that your domain's DNS information has changed and needs to be updated.

Email Verification

Correct SOA Serial Number Format

This number must be in a specific format: a simple integer that is usually formatted as YYYYMMDDNN, where YYYY is the year, MM is the month, DD is the day, and NN is a counter for changes within the day.

For example, if you updated your DNS records for the first time on February 10, 2024, your serial number might look like this: 2024021001. If you made another change later that same day, the serial number would update to 2024021002 to reflect the second change. This system helps ensure that all changes are tracked and propagated correctly across the internet.

Sample output from our DNS testing tool for domain wikipedia.org:

Invalid SOA Serial Number Format

However, if the serial number is not in the correct format or sequence, other servers might not recognize the updates, leading to discrepancies in DNS information. This can result in emails not reaching their destination or being delayed. For instance, a serial number like 24022001 (missing the '20' at the beginning of the year) or 20240210AB (using letters instead of numbers) would be considered invalid.

Regular DNS Testing Prevents Failure

To keep your email systems running smoothly, it's important to regularly check your DNS configurations, including the SOA record's serial number.

Ensure it follows the correct format and sequence. Regular audits can help catch misconfigurations early, preventing potential email delivery issues. Remember, in the digital world, attention to detail can make all the difference in ensuring your emails reach their audience.