What is DNS Lookup?
DNS (Domain Name System) lookup is the process of translating a domain name into an IP address. When an email is sent, the email server performs a DNS lookup to find the IP address of the recipient's server. This is essential for routing the email to its intended destination.
Why is DNS Lookup Important in Email Marketing?
DNS lookup is crucial in email marketing because it ensures that emails are delivered to the correct servers. It also plays a key role in verifying the
authenticity of the email sender through mechanisms like
SPF (Sender Policy Framework),
DKIM (DomainKeys Identified Mail), and
DMARC (Domain-based Message Authentication, Reporting & Conformance).
What is DNS Lookup Limit?
The DNS lookup limit refers to the maximum number of DNS queries that can be performed during the email authentication process. Most email providers set this limit to a maximum of 10 DNS lookups to prevent
DNS-based attacks and ensure quick email processing.
How Does DNS Lookup Limit Affect Email Deliverability?
If your email authentication records (SPF, DKIM, DMARC) require more than the allowed number of DNS lookups, the authentication process may fail. This can lead to emails being marked as
spam or even rejected by the recipient's server, adversely affecting your email deliverability.
Consolidate your SPF records: Combine multiple IP addresses into a single range or use fewer include statements.
Use Subdomains: If you have multiple sending domains, use subdomains to separate them and reduce the load on a single DNS record.
Optimize DKIM and DMARC records: Ensure that these records are concise and do not require additional DNS lookups.
What Happens if You Exceed the DNS Lookup Limit?
If your email authentication records exceed the DNS lookup limit, the email server will not be able to complete the authentication process. This often results in the email being flagged as suspicious or even rejected, thereby harming your
sender reputation and overall deliverability.
Conclusion
Understanding and managing DNS lookup limits is critical for effective email marketing. Ensure that your email authentication records are optimized to stay within the allowed limits, thereby enhancing your email deliverability and maintaining a good sender reputation.