DNS
What is DNS Propagation?
The delay before a DNS change is visible everywhere as cached copies of the old record expire.
DNS propagation is the informal term for the time it takes a record change to be seen by all resolvers worldwide. It is driven primarily by the previous record's TTL and resolver caching rather than by any active spreading of data, so updates appear at different times in different places. The authoritative change is immediate at the source; the lag is entirely cached copies of the old value timing out.
Why it matters for cold email
After adding SPF, DKIM, DMARC, or MX records for a new cold-email domain, you must wait for propagation before sending or verifying authentication, because tools and receivers may still see the old or absent records. Sending too soon produces unauthenticated mail that damages a fresh domain's reputation from day one.
Related terms
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