Summary
After fixing DNS records following a DNS provider change, the recommended waiting time before sending emails varies considerably. Estimates range from as little as 4-8 hours to as much as 72 hours, influenced by factors like Time-To-Live (TTL) settings, ISP caching, and whether any NXDOMAIN errors were encountered during the change. Several sources emphasize checking the SOA record for cache time limits and consistently recommend actively monitoring DNS records (including SPF and DKIM) to confirm propagation before resuming email sending. If no emails were sent during the outage, then the NXDOMAIN error can be ignored. It is generally accepted that shorter TTLs lead to faster propagation.
Key findings
- Varied Propagation Times: DNS propagation times exhibit significant variability, ranging from a few hours to three days, dependent on various factors.
- TTL's Influence: TTL settings critically affect propagation speed; shorter TTLs facilitate faster updates.
- Importance of Monitoring: Consensus exists across all sources regarding the necessity to monitor DNS records actively.
- SOA Record Relevance: The SOA record provides essential information about caching parameters.
- NXDOMAIN Impact: NXDOMAIN caching only effects sending if lookups failed while the DNS was broken.
Key considerations
- Assess Previous TTL: Determine the TTL settings of the old DNS records as this influences the propagation time of the new records.
- Account for ISP Caching: Recognize that ISP caching can extend propagation times beyond expected durations.
- Monitor DNS Records: Regularly monitor DNS records, including SPF and DKIM, to verify complete propagation before resuming sending.
- Check SOA Record: Examine the SOA record to understand the upper limit for DNS caching to know how long you have to wait.
- Impact of NXDOMAIN: Evaluate sending activity during the broken DNS period to assess any NXDOMAIN impacts.
What email marketers say
5 marketer opinions
After changing DNS providers and updating DNS records, the recommended waiting time before sending emails varies. While some sources suggest a range of 24-72 hours for complete propagation, others indicate that it can be as quick as 4-8 hours or up to 24-48 hours, depending on factors like TTL settings and ISP caching. Monitoring DNS records using online tools is consistently advised to ensure the updates have propagated correctly across different locations before resuming email sending. The TTL of the previous records greatly effects the answer. If DNS records aren't validated, there are deliverability issues.
Key opinions
- Propagation Time Variance: DNS propagation times vary significantly, ranging from a few hours to several days.
- Importance of Monitoring: Consistently advised to monitor DNS records to ensure updates have propagated correctly before resuming sending.
- Impact of TTL: TTL (Time To Live) settings of the previous DNS records greatly affects how long it takes for changes to propagate.
Key considerations
- TTL Settings: Consider the TTL settings of the previous DNS records when estimating waiting time. Shorter TTLs result in faster propagation.
- ISP Caching: Be aware that ISPs cache DNS records, which can prolong propagation times beyond initial estimates.
- DNS Record Validation: Validate DNS records (SPF, DKIM) to avoid deliverability issues. Ensure email authentication is working correctly.
Marketer view
Email marketer from Reddit user u/DNS_Query shares that it's safe to send emails after 24 hours after changing the DNS records, but strongly recommend to monitor the key DNS records to ensure they are propogating correctly and aren't failing authentication.
12 Jun 2023 - Reddit
Marketer view
Email marketer from MXToolbox recommends waiting 48-72 hours for complete DNS propagation after making changes, especially for critical records like SPF and DKIM. They also advise monitoring DNS records during this period to ensure they're updating correctly.
21 Jul 2023 - MXToolbox
What the experts say
3 expert opinions
Determining how long to wait before sending email after fixing DNS records hinges on a few factors. Checking the SOA record provides the upper limit on cache time. The impact of NXDOMAIN caching depends on whether anyone received the error; if no email was sent during the broken DNS period, there's no concern. TTL settings also play a crucial role, with shorter TTLs enabling faster propagation. Consistently, monitoring DNS records to confirm updates is vital before resuming sending.
Key opinions
- SOA Record Importance: The SOA record indicates the upper limit for DNS caching, which is crucial for determining the maximum waiting time.
- NXDOMAIN Impact: NXDOMAIN caching only matters if there were failed lookup attempts during the period the DNS was broken. If not, it's not a factor.
- TTL Relevance: TTL settings directly influence propagation speed. Shorter TTLs lead to faster updates.
Key considerations
- Check SOA: Always check the SOA record to understand the upper limit for DNS caching.
- Assess NXDOMAIN: Determine if email sending occurred while DNS was broken to evaluate the impact of NXDOMAIN caching.
- Monitor DNS Records: Actively monitor DNS records after changes to confirm successful propagation before resuming email sending.
Expert view
Expert from Email Geeks explains that the NXDOMAIN will only be cached if someone got that response, so the time you sent email after the DNS was broken will affect it. If no mail was sent, all is good.
27 Apr 2023 - Email Geeks
Expert view
Expert from Email Geeks shares to check the SOA record to see how long the cache time is, which is the upper limit on pain after the records were fixed.
16 Dec 2021 - Email Geeks
What the documentation says
3 technical articles
Documentation from multiple sources indicates varying propagation times for DNS changes. Google Workspace Admin Help suggests up to 72 hours, while Cloudflare estimates 24-48 hours, attributing the delay to ISP caching. DigitalOcean highlights the influence of TTL values, with lower TTLs leading to faster propagation. A consistent recommendation across all sources is to verify DNS record updates before resuming email sending.
Key findings
- Variable Propagation Times: DNS propagation times can vary, ranging from 24 to 72 hours, influenced by factors like ISP caching.
- TTL Influence: TTL (Time To Live) values significantly impact propagation speed; lower TTLs result in faster updates.
- Importance of Verification: Verifying DNS record updates before resuming email sending is a consistent recommendation.
Key considerations
- ISP Caching: Account for potential delays due to ISP caching, which can prolong propagation times.
- TTL Management: Manage TTL values strategically to influence DNS propagation speed; consider using lower TTLs for faster updates.
- DNS Record Checks: Implement DNS record checks using tools like Google Admin Toolbox Dig or command-line tools to confirm updates before resuming email sending.
Technical article
Documentation from DigitalOcean answers that most DNS servers respect TTL values. Low TTLs cause faster propagation than High TTLs. Also they recommend to check your DNS records to confirm propagation before sending emails.
20 Jun 2022 - DigitalOcean
Technical article
Documentation from Cloudflare states that while their DNS changes are typically fast, complete propagation across the internet can still take up to 24-48 hours due to caching by ISPs. They suggest verifying the new records using command-line tools or online DNS checkers.
10 Aug 2021 - Cloudflare
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