Summary
Building an email allow list using MX records involves classifying domains based on their MX records, identifying known MX patterns for major providers (e.g., AOL, Outlook, Microsoft, Yahoo), and caching these records for faster validation due to their relative stability. MX records, found in DNS settings, specify mail servers responsible for accepting emails and include priority numbers; lower numbers are tried first. Continuous monitoring and updates are essential for maintaining an accurate allow list. Feedback loops can also improve whitelisting effectiveness by providing insights into audience engagement.
Key findings
- MX Record Classification: Classifying domains by their MX records aids in building allow lists.
- MX Record Stability: MX records are relatively stable, making caching a viable strategy.
- MX Record Examples: Specific MX record patterns identify major email providers.
- DNS Settings: MX records reside in DNS settings provided by the domain host.
- MX Priority: MX records have a priority; lower numbers are attempted first.
Key considerations
- Continuous Monitoring: Regular updates and monitoring are necessary to maintain allow list accuracy.
- Feedback Loops: Utilizing feedback loops can enhance whitelisting effectiveness.
- DNS Access: Access to DNS settings is needed to modify or check MX records.
What email marketers say
11 marketer opinions
Building an email allow list using MX records involves querying MX records to identify known good domains and caching those results for quick validation of new sign-ups. This includes checking domains against known MX records of major providers like Microsoft and Yahoo. Verifying that a domain has valid MX records is a basic step in ensuring deliverability, as MX records point to the mail servers responsible for accepting email messages on behalf of a domain. Also note MX records can point to subdomains as well as the primary domain, allowing for flexible email routing configurations.
Key opinions
- MX Record Validation: MX record verification is a fundamental step in ensuring email deliverability.
- Caching MX Records: Caching MX records of known good domains enables faster validation processes.
- Identify Major Providers: Checking MX records against known MX records of major providers like Microsoft and Yahoo is helpful.
- MX record flexibility: MX records can point to subdomains as well as the primary domain.
Key considerations
- Continuous Monitoring: Allow lists require continuous monitoring and updates due to dynamic domain configurations.
- Deliverability Impact: Validating MX records is a basic step for email deliverability.
- MX Records Role: MX records indicate which mail servers are responsible for accepting emails.
Marketer view
Email marketer from SparkPost explains that MX records point to the mail servers responsible for accepting email messages on behalf of a domain. Verifying that a domain has valid MX records is a basic step in ensuring deliverability.
19 Oct 2024 - SparkPost
Marketer view
Email marketer from Email Hippo shares using MX records in email verification helps determine whether a domain accepts email, and this, is one factor, in determining whether an email address is likely to be valid and active.
12 Mar 2023 - Email Hippo
What the experts say
6 expert opinions
Building an email allow list using MX records involves classifying domains based on their MX records and adding domains with known MX patterns to the allow list. Caching MX records is possible since they don't change frequently. Examples of MX records include mx-aol.mail.gm0.yahoodns.net for AOL and outlook-com.olc.protection.outlook.com for Outlook. Maintaining an accurate allow list requires continuous monitoring, and feedback loops can provide insights into audience engagement to improve whitelisting.
Key opinions
- MX Record Classification: Classifying domains by MX records is a method for building allow lists.
- MX Record Stability: MX records are relatively stable and suitable for caching.
- MX Record Examples: Known MX patterns identify major providers (e.g., AOL, Outlook).
Key considerations
- Continuous Monitoring: Maintaining an accurate allow list necessitates continuous monitoring and updates.
- Feedback Loops: Feedback loops can improve whitelisting effectiveness by providing audience insights.
Expert view
Expert from Spam Resource explains that maintaining a current and accurate allow list based on MX records involves continuous monitoring and updates due to the dynamic nature of domain configurations.
2 Dec 2024 - Spam Resource
Expert view
Expert from Email Geeks provides examples of MX records, like mx-aol.mail.gm0.yahoodns.net for AOL and outlook-com.olc.protection.outlook.com for Outlook.
4 May 2025 - Email Geeks
What the documentation says
5 technical articles
Building an email allow list requires understanding MX records, which are found in DNS settings. These records specify the mail server for a domain and include a preference number; lower numbers are tried first. You can add/modify these in domain control panels, with considerations for TTL: low TTL for faster propagation and high TTL for less frequent lookups. MX records specify the mail server responsible for accepting emails for a domain, including a preference value.
Key findings
- MX Record Location: MX records are located in DNS settings at your domain host.
- MX Record Priority: MX records have priority numbers; lower numbers are tried first.
- MX Definition: MX records specify mail servers for accepting emails on behalf of a domain.
Key considerations
- DNS Configuration: Adding and modifying MX records requires accessing your DNS control panel.
- TTL Setting: The TTL setting impacts propagation speed and lookup frequency of MX records.
Technical article
Documentation from Microsoft Learn explains that the MX record with the lowest preference number (highest priority) is tried first. If it fails, the next MX record in priority sequence is used.
5 Aug 2024 - Microsoft Learn
Technical article
Documentation from Google explains that you can find MX records in your DNS settings provided by your domain host. Log in to your domain host's website, locate the DNS settings, and look for MX records.
13 Mar 2023 - Google
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