If you've recently updated a DNS record for your domain — an MX record, an SPF entry, or anything else — and it doesn't seem to be working yet, you're probably running into DNS propagation. This is completely normal, and understanding how it works will save you a lot of unnecessary troubleshooting.
What is DNS propagation?
DNS propagation is the time it takes for a DNS change to become visible everywhere on the internet. When you update a record in your domain's DNS zone, that change doesn't instantly appear everywhere at once. Instead, it has to spread across a huge, distributed network of DNS resolvers and caches operated by ISPs, hosting providers, and public DNS services around the world.
Until every one of those caches refreshes, some people will see your new record and others will still see the old one. This is why a DNS change can appear to be "working" for you but not yet for a colleague on a different network, or why a mail server somewhere might route a message using outdated information for a short while.
Why propagation isn't instant
A record's Time to Live (TTL) setting controls how long DNS resolvers are allowed to cache it before checking for updates again. A resolver that cached your old record with a 24-hour TTL won't ask for a fresh copy until that 24 hours is up, even though you already changed it. Beyond TTL, propagation speed is also affected by which DNS provider you use, how various ISPs handle caching, and general network conditions across different regions.
Typical propagation times
These are general ranges — actual timing varies by provider and record type:
- A / CNAME records: roughly 30 minutes to 48 hours
- MX records: roughly 4 to 24 hours
- SPF, DKIM, DMARC (TXT records): roughly 30 minutes to 24 hours
- Nameserver changes: roughly 24 to 48 hours, occasionally longer
How propagation delays can affect email
While DNS changes are still spreading, you may temporarily see:
- Bounced or delayed messages if an MX record change hasn't reached every resolver yet
- SPF or DKIM authentication failures if an updated TXT record isn't visible everywhere, which can push otherwise-legitimate mail into spam
- Inconsistent results — some recipients receive mail normally while others see delivery issues, simply depending on which DNS cache their provider is using
None of this means the change was done incorrectly. It usually just means the internet hasn't fully caught up yet.
How to make changes smoothly
- Lower the TTL in advance. If you're planning a DNS change, lowering the TTL to something short (a few minutes) a day beforehand means the old record expires from caches faster once you make the real change. You can raise the TTL back to normal afterward.
- Make changes during low-traffic periods if you're able to, so fewer people are affected by any temporary inconsistency.
- Check propagation status with a public DNS lookup tool before assuming something is broken — many tools show you what different locations around the world are currently seeing.
- Be patient before re-testing. Give a change at least a few hours, and up to 48–72 hours in unusual cases, before concluding it hasn't taken effect.
Common issues
I updated my SPF record but I'm still failing authentication checks. This is often a propagation delay rather than a configuration error — wait a few hours and re-test. If it's still failing after 24–48 hours, double check the record's syntax.
Can Avalon Hosting speed up propagation? Propagation timing is largely outside any single provider's control since it depends on DNS resolvers across the internet. If you manage your domain's DNS through your Avalon hosting control panel and have questions about a specific change, Avalon Hosting support can confirm the record was saved correctly on our end.
