MX and SPF: receiving versus sending

Do not infer sending permission from MX or treat TXT inspection as a delivery test.

MX describes incoming mail routing

MX points to servers responsible for receiving mail for a domain. Lower preference numbers are normally tried first. Multiple MX answers can be a normal redundancy arrangement. Compare each value with your mail provider’s requirements before changing it.

SPF describes sending authorization

SPF is usually published in TXT text beginning with v=spf1. It concerns which servers may send on behalf of a domain rather than selecting the receiving server. Viewing the text is different from fully evaluating the policy and its recursive mechanisms.

Delivery requires more evidence

Even when MX and SPF appear correct, delivery can depend on DKIM, DMARC, message content and server reputation. This tool displays DNS records. It does not send a test message or calculate a deliverability score.

This guide explains public DNS responses. Before changing production settings, check the documentation for your current domain and hosting providers.