What is the impact of changing nameservers on email deliverability?
Michael Ko
Co-founder & CEO, Suped
Published 29 Jul 2025
Updated 19 Aug 2025
8 min read
Changing nameservers is a significant technical change for any domain. Nameservers are the backbone of the Domain Name System (DNS), essentially directing internet traffic, including your emails, to the correct servers. While often seen as a task primarily affecting websites, the impact on email deliverability can be substantial if not managed meticulously. The primary concern revolves around the proper migration of your DNS records, particularly those crucial for email.
When you switch nameservers, you are telling the internet that a new set of servers is now responsible for handling all DNS queries for your domain. This includes locating your website, but more importantly for email, it includes directing incoming mail and authorizing outgoing mail. A misstep here can lead to emails bouncing, being marked as spam, or simply not reaching their intended recipients, potentially causing significant disruption to your communication flow.
Understanding nameservers and DNS
Nameservers are pivotal because they hold the authoritative DNS records for your domain. These records, such as MX, SPF, DKIM, and DMARC, are vital for email functionality and security. The act of changing nameservers means you are pointing your domain to a new DNS provider, which then becomes responsible for serving these records. If these critical email-related DNS records are not accurately replicated at the new nameserver host, email systems will struggle to verify your domain.
For instance, the Mail Exchange (MX) record tells other mail servers where to send your incoming email. If this record is incorrect or missing after a nameserver change, your domain will stop receiving emails. Similarly, Sender Policy Framework (SPF) records, DomainKeys Identified Mail (DKIM) records, and Domain-based Message Authentication, Reporting & Conformance (DMARC) records are used by recipient mail servers to authenticate your outgoing email. Without these, your emails are highly likely to be flagged as suspicious or spam, affecting overall email deliverability.
The DNS propagation process also plays a role. When nameservers are updated, it takes time for these changes to disseminate across the internet. This period, known as propagation, can last up to 48 hours, though it's often much quicker. During this transition, some parts of the internet might still be looking at your old nameservers, while others have updated to the new ones. This inconsistency can lead to temporary email delivery failures as mail servers attempt to resolve your domain's records from different sources.
Potential impacts on email deliverability
One of the most immediate impacts of an unmanaged nameserver change is email downtime. If the MX records are not correctly transferred, incoming emails will have nowhere to go. Similarly, without proper SPF, DKIM, and DMARC records, your outgoing emails will fail authentication checks at recipient servers. This can lead to a surge in bounces and a significant drop in your email deliverability rates.
Beyond immediate failures, there's a risk to your sender reputation. Email providers meticulously track your domain's sending behavior. If your emails suddenly start failing authentication or bouncing in large numbers due to DNS misconfigurations, it signals poor sending practices. This can lead to your domain being put on internal blocklists (or blacklists) by individual mailbox providers, meaning your emails might go straight to spam folders even after the DNS issues are resolved.
It's also worth noting that changing nameservers can indeed affect your email directly. While the core domain changing IPs wouldn't typically impact subdomains if they have their own DNS delegation, a fundamental issue at the main nameserver level can cause resolution problems across your entire domain structure. This underscores the need for thorough checking of new IP addresses against any existing blocklists (or blacklists) before a transition.
Mitigation strategies for a smooth transition
To minimize disruption, careful planning is essential. Before making any changes, retrieve all existing DNS records from your current nameserver provider, especially your MX, SPF, DKIM, and DMARC records. You can use a simple guide to DMARC, SPF, and DKIM to ensure you have a complete list of what needs to be migrated. Double-check all values to prevent typographical errors.
When configuring the new nameservers, ensure that all these critical DNS records are replicated exactly as they were. This includes any subdomain-specific records that might be in use. It is a good practice to reduce the TTL (Time to Live) values for your records a day or two before the change. A lower TTL ensures that changes propagate faster across the internet, minimizing the window of potential disruption.
Preparation
Audit existing records: List all current DNS records, including MX, SPF, DKIM, DMARC, A, and CNAME records.
Reduce TTL: Lower the Time To Live for all records to 300 seconds (5 minutes) or less.
Verify new DNS provider capabilities: Confirm they support all necessary record types for email authentication.
Migration
Replicate records: Accurately add all copied DNS records to your new nameserver provider.
Update nameservers: Change your domain's nameservers at your domain registrar to the new provider's nameservers.
Overlap period: Maintain old nameservers alongside new ones for a short period if possible.
Post-migration monitoring and verification
Once the nameserver change has been initiated, continuous monitoring is crucial. Use DNS lookup tools to verify that your domain's DNS records are correctly resolving from the new nameservers. Pay particular attention to your MX records to ensure incoming email continues to flow. You can use an email deliverability test to confirm your messages are reaching inboxes.
It's also essential to monitor your DMARC reports. These reports provide invaluable insights into email authentication failures and help you quickly identify any issues stemming from the nameserver change. If you see a sudden spike in SPF or DKIM failures, it's a strong indicator that something went wrong during the DNS record migration. Regular review of your email sender guidelines and DMARC data can save you from prolonged deliverability issues.
Furthermore, keep an eye on blocklists (or blacklists). While a nameserver change itself doesn't directly put you on a blocklist, issues arising from misconfiguration can. For instance, if your new IP addresses are already associated with problematic sending history, it could lead to deliverability problems. Regularly checking if your domain or sending IP has landed on any major blocklists is a critical part of post-migration oversight. Knowing what happens when your domain is on an email blacklist is important for swift remediation.
Finally, ensure that any other services tied to your domain, such as website hosting or CDN, are also resolving correctly. While this article focuses on email, a holistic check helps ensure overall domain health and prevents cascading issues that could indirectly affect email performance.
Views from the trenches
Best practices
Always back up all your existing DNS records before initiating any nameserver changes.
Lower TTL values for DNS records a day or two before the migration to speed up propagation.
Verify all critical DNS records (MX, SPF, DKIM, DMARC) are accurately transferred to the new nameservers.
Conduct thorough testing of both inbound and outbound email delivery immediately after the change.
Common pitfalls
Forgetting to migrate all necessary DNS records, especially email authentication records.
Not reducing TTL values, leading to prolonged propagation and potential service disruptions.
Assuming new IP addresses are clean without checking for existing blocklist entries.
Failing to monitor DMARC reports for authentication failures post-migration.
Expert tips
Consider a phased migration if possible, starting with lower-volume domains.
Use a tool to monitor DNS propagation in real-time to catch issues early.
Communicate potential temporary disruptions to stakeholders internally and externally.
Have a rollback plan in place in case significant issues arise during the transition.
Expert view
Expert from Email Geeks says changing nameservers is very unlikely to cause issues if done correctly.
2019-11-18 - Email Geeks
Marketer view
Marketer from Email Geeks says improper migration or transition periods can cause DNS resolution issues, suggesting an overlap for a few days.
2019-11-18 - Email Geeks
Navigating nameserver changes for email success
Changing nameservers for your domain is a critical administrative task with a direct impact on email deliverability. While it might seem like a backend change, the correct migration of your email-related DNS records is paramount to prevent service disruption, authentication failures, and damage to your sender reputation. A failure to correctly transfer these settings can lead to emails not being delivered, increased spam classifications, and a general loss of trust from recipient mail servers.
The key to a successful nameserver migration, particularly concerning email, lies in meticulous planning, careful execution, and vigilant post-migration monitoring. By understanding the role of DNS in email flow, ensuring all necessary records are accurately replicated, and proactively checking for any issues like blocklist (or blacklist) placements, you can ensure your email communication remains uninterrupted and your deliverability rates stay strong. Prioritizing these steps will help you navigate the change without significant impact.
