What is a recommended TTL for SPF/DKIM/DMARC records?

Authentication record TTL recommendations:

SPF:

Normal: 3600-86400 seconds

During changes: 300-600 seconds

SPF rarely changes for stable setups.

DKIM:

Normal: 3600-86400 seconds

Key rotation: Lower TTL before, during, after rotation

Longer TTL is fine since selectors change rather than records being modified.

DMARC:

Normal: 3600-86400 seconds

Policy changes: Lower temporarily

Especially when moving from none to quarantine to reject.

Standard approach: 3600 seconds provides good balance for most situations.

Credential validity periods. Stable credentials can have longer validity.