Skip to main content

What’s the role of authentication in MTA configuration?

MTAs must be configured to properly authenticate outbound email. This includes DKIM signing (adding cryptographic signatures), SPF alignment (sending from authorized IPs), and ensuring messages pass DMARC checks at receiving servers.

DKIM configuration involves: generating key pairs, publishing public keys in **DNS**, and configuring the **MTA** to sign messages with the private key. Selector management allows key rotation without disruption.

SPF alignment requires sending from IP addresses listed in **DNS** **SPF** records. MTAs must use correct envelope sender addresses matching the authorized domain. Misconfigurations cause authentication failures that harm deliverability regardless of content quality.