SPF publishes authorised sending servers in a DNS text record. A receiving server can check the sending server against the record for the email’s return-path domain. Cloudflare explains that this is an email authentication mechanism; it concerns the sending infrastructure rather than the wording of the message. Source: Cloudflare: SPF records

List the systems that send email

Include the office email service, marketing platform and any booking or enquiry system that sends on the business’s behalf. Ask the email provider to review the list against the current record. This gives the review a complete starting point.

Test after an agreed change

Have the responsible provider confirm the required values before any DNS update. Then test a message from each approved sending system and review the authentication results. This checks the actual sending routes instead of assuming one successful office email covers every platform.

Written and updated by Travelgenix. Sources checked on 19 October 2026. Practical advice and examples are Travelgenix editorial guidance.