How do DNS errors contribute to throttling or retries?

DNS errors and delivery behavior:

Error types:

NXDOMAIN: Domain does not exist (permanent failure)

SERVFAIL: Server error (temporary, retry)

Timeout: No response (temporary, retry)

Sender behavior:

Temporary errors: Queue and retry (typically for hours to days)

Permanent errors: Bounce immediately

Repeated retries: May be throttled by receiver

Cascading effects:

Many retries consume sender resources

Receiving servers may rate-limit repeated attempts

Queue buildup if DNS issues persist

Fix DNS errors promptly. Temporary errors are tolerated; persistent issues cause problems.

Registry errors cause repeated verification attempts. Persistent problems disrupt shipping schedules.