Email Authentication for School Newsletters: SPF, DKIM, and DMARC Explained

Email authentication records are the technical foundation that determines whether your school newsletter is recognized as legitimate by the email providers that deliver it to families. Teachers do not need to understand the technical details of how these records work. They do need to understand why they matter, what to ask their IT department to set up, and how to verify that the setup is correct. This article gives you that practical understanding without requiring a background in DNS or email infrastructure.

The Problem Authentication Solves

Anyone can send an email that claims to be from principal@yourschool.edu. Without authentication records, email providers have no way to verify whether a message claiming to come from your school domain actually originated from an authorized server. This is the same vulnerability that enables phishing attacks where criminals send emails impersonating trusted organizations. Email authentication records add a verification layer. When your newsletter sends, receiving mail servers check the authentication records on your domain. If the checks pass, the email is legitimate. If they fail, the email is treated with suspicion. Schools that have not configured authentication are sending newsletters with no verification signal, which increases spam placement rates.

SPF: The List of Authorized Senders

SPF is a DNS record that lists the mail servers allowed to send email on behalf of your domain. When a receiving mail server gets an email from principal@yourschool.edu, it checks the SPF record for yourschool.edu to see whether the server that sent the email is on the authorized list. Your newsletter platform will provide the specific text to add to your SPF record. If your school already has an SPF record for its regular email service, the newsletter platform value needs to be added to the existing record rather than creating a duplicate. Your IT coordinator handles this. The resulting SPF record covers both your school's regular email and your newsletter sending service.

DKIM: The Digital Signature

DKIM works by adding a cryptographic signature to each outgoing email. The signature is generated using a private key held by your newsletter platform. A corresponding public key is published in your domain's DNS records. When a receiving mail server gets your newsletter, it looks up the public key in your DNS, uses it to verify the signature in the email, and confirms that the email came from an authorized sender and was not modified in transit. Your newsletter platform generates the DKIM record value for you to add to your DNS. It looks like a long string of seemingly random characters. Your IT team adds this record to your domain's DNS exactly as provided. No modification is needed.

DMARC: The Policy Layer

DMARC builds on SPF and DKIM by adding a policy that tells receiving mail servers what to do when authentication fails. A DMARC policy of “none” monitors authentication results without taking action. A policy of “quarantine” sends failing emails to the spam folder. A policy of “reject” blocks failing emails from delivery entirely. Start with a DMARC policy of “none” while you verify that SPF and DKIM are working correctly. Switching to “quarantine” or “reject” before your authentication is fully working can cause legitimate school emails to be blocked. DMARC also includes a reporting address that receives reports from email providers about authentication results, which helps you monitor how your school domain is being used.

What to Ask Your IT Department

When you need your IT department to configure email authentication for a school newsletter, bring them the specific values your newsletter platform provides. Tell them you need three DNS record additions or modifications: an SPF record update, a new DKIM TXT record, and a new DMARC TXT record. Provide the exact record values from your newsletter platform's setup documentation. Ask them to add the records and confirm when the changes have propagated. DNS changes typically take between fifteen minutes and 24 hours to propagate fully. Test the authentication after propagation using Mail-tester.com rather than immediately after the records are added.

Common Setup Mistakes to Avoid

The most common authentication setup mistake is having multiple SPF records on a domain, which is invalid. A domain can have only one SPF record. If your school already has an SPF record for regular email, the newsletter platform's sending servers must be added to that existing record, not as a separate record. The second common mistake is getting the DKIM selector wrong. Your newsletter platform will specify which selector to use. The DNS record name is the selector followed by “._domainkey.yourdomain.edu.” If your IT team uses the wrong selector name, DKIM will fail. Third, do not set DMARC to “reject” until you have confirmed that SPF and DKIM are both passing for all legitimate sending sources. Jumping to reject before verification can block legitimate school emails.

Maintaining Authentication Over Time

Once email authentication is set up correctly, it requires minimal maintenance. The records stay in place and continue working. Maintenance is needed when you change newsletter platforms, because the DKIM keys and SPF includes may change, or when your school switches to a new email provider for regular email. Any time you change the infrastructure that sends email on behalf of your domain, review your authentication records to ensure they still match what is actually sending. Set a reminder to verify authentication annually as part of your school communication technology review.