VPS content image
← Back

Updated at: 08/03/2024

PTR Record: Configuration & Email Deliverability

Share this post:

As an advanced professional, understanding the importance of PTR records in email deliverability is crucial to maintaining a secure and efficient mailing system. This blog post dives into the world of PTR records and provides valuable insights on how Reverse Pointers authenticate sender identities, protect against spammers, and improve overall email server reliability.

In addition to exploring best practices for configuring and managing PTR records using various tools like dig, nslookup commands, MxToolbox, we will also discuss working with VPS Hosting Providers to create these essential DNS entries. You'll learn about ensuring each A-record has a corresponding PTR Record as well as the differences between IPv4 (.arpa) & IPv6 (.ip6.arpa) namespaces.

Furthermore, this post highlights guidelines when setting up multiple entries per IP address for mailing servers while considering their limitations. Lastly, you'll discover how properly configured PTR records can enhance analytical capabilities by avoiding bounce backs and improving email security while identifying fraudulent domains used by spammers.

VPS content image

Importance of PTR Records in DNS

PTR records are like the bouncers of the internet, ensuring that only legitimate mail servers get past the velvet rope. They do this by mapping an IP address to a hostname, enabling reverse DNS lookups that help verify the sender of an email message and prevent spamming.

Reverse DNS Lookups for Verifying Senders

A reverse DNS lookup is like a background check for email senders. It retrieves the hostname associated with an IP address and compares it against other identifying data stored in the domain's DNS. This process helps prevent spammers from using fake or forged addresses to bypass spam filters.

Preventing Spamming Activities

PTR records are like the bouncers of the email world, keeping out unwanted guests. They play a crucial role in combating spammers who often use illegitimate tactics such as sending emails from spoofed IP addresses or domains without proper authentication mechanisms in place.

  • DNS-based Blackhole Lists (DBLs): An effective anti-spam tool, DBLs maintain lists of IP addresses and domains associated with spamming activities. Upon receipt of an email from a listed source, mail servers can either deny the message or mark it as spam.
  • Sender Policy Framework (SPF): This is another authentication method that helps prevent spoofing by verifying if the sender's IP address is authorized to send emails on behalf of the domain in question. It does this by checking against SPF records stored within the domain's DNS.

Properly configured PTR records can significantly impact email deliverability, improving your mail server's credibility while protecting recipients from potential spam threats.

Configuring PTR Records for Mail Servers

Properly configuring PTR records is vital for ensuring reliable email delivery and protecting against spammers. Most mail providers reject or mark messages received by mail servers without valid Reverse DNS configuration as SPAM. Learn how to setup
Reverse DNS configuration for your EDIS Global VPS Hosting.

Impact on Email Deliverability

A well-configured PTR record ensures that recipient email systems can verify that incoming emails originate from legitimate sources associated with specific domains. This helps prevent spoofing attempts and improves overall deliverability rates by reducing instances where genuine emails end up in recipients' spam folders due to failed sender verification checks performed using tools such as Sender Policy Framework (SPF) and DomainKeys Identified Mail (DKIM).

It is also essential to set up other email authentication mechanisms like SPF and DKIM to ensure that your emails are not only delivered but also trusted by recipient mail servers. Regular monitoring of these settings using online tools like MxToolbox or manual checks using commands like dig and nslookup on Windows, Linux, or macOS systems will help maintain optimal email deliverability rates for your organization.

Checking and Setting Up PTR Record Values

Ensure your domain has properly set up its PTR record value by performing manual checks using dig and nslookup commands from Windows, Linux, or macOS systems. These commands help you verify the existence of a reverse DNS entry for an IP address. Alternatively, use online tools like MxToolbox for quick reverse lookup results.

Using dig and nslookup Commands

In Linux or macOS, use

dig -x [IP_ADDRESS]

and replace [IP_ADDRESS] with the actual IPv4 or IPv6 address.

In Linux or macOS, use

nslookup [IP_ADDRESS]

and replace [IP_ADDRESS] with the actual IPv4 or IPv6 address.

Online Tools like MxToolbox

Use web-based services like MxToolbox for a user-friendly approach to check PTR records quickly. Input the IP address, and it will display the corresponding PTR record if available.

If no PTR record exists for your domain's IP address or if there are inconsistencies in its configuration, contact your hosting provider or ISP immediately. They should be able to assist you with setting up a proper reverse DNS entry that matches your forward DNS records. Accurate PTR records are essential for reliable email deliverability and avoiding potential issues related to spam filtering.

Keeping Your Records Updated

  • Regularly check both forward and reverse DNS entries using tools mentioned above.
  • Update PTR records promptly when changes need to be made.
  • Maintain accurate documentation of all DNS configurations, including A-records, MX-records, CNAMEs, TXT records, etc., as part of best practices for managing IT infrastructure.

A-Record Correspondence and IPv4/IPv6 Considerations

Properly configuring PTR records is crucial for maintaining a reliable DNS system. Each A-record must have a corresponding PTR record to enable accurate reverse lookups, which contribute to improved email deliverability and reduced spamming activities.

Matching A-Record with Appropriate PTR Record

An A-record maps a domain name or subdomain to an IP address, while a PTR record maps an IP address back to its associated hostname through reverse DNS lookup. To ensure proper identification of senders during mail delivery processes, you must create a matching PTR record for each existing A-record.

  • A-Record: example.com ->
  • PTR Record: -> example.com

This bidirectional relationship allows mail servers to verify if the sender matches their claimed domain's DNS information.

PTR Records and Email Deliverability

They ensure that only legitimate emails get through to the recipient's inbox. Don't fret if PTR records are unfamiliar to you; EDIS Global VPS Hosting Support Team will guide you how to correctly set one up.

What are PTR Records?

PTR records, also known as pointer records, are a type of DNS record that stores identifying information about an IP address. PTR records are employed in tandem with A-records to guarantee that the IP address of a mail server is consistent with the domain name of the email sender.

Why are PTR Records Important for Email Deliverability?

When a mail server receives an email, it performs a reverse DNS lookup on the sender's IP address to verify that it matches the domain name of the email sender. If there is no matching PTR record or if it does not correspond with the A-record, the email may be flagged as spam and sent directly to the recipient's junk folder.

How to Check and Add PTR Records

Checking and adding PTR records is easy. You can use tools like MXToolbox to check if your PTR records are set up correctly. If you need to add PTR records, login to your EDIS Global VPS Panel and configure a PTR record. 

Using Mailtrap Email Sandbox for Testing

To ensure that your emails are delivered to the recipient's inbox, you can use tools like Mailtrap Email Sandbox to test your messages before sending them out en masse. This tool allows you to send test emails through its platform simulating real-world conditions so that you can identify possible issues with your current configuration.

  1. Sign up at Mailtrap, create a new inbox within their dashboard which will provide SMTP credentials required for testing purposes.
  2. Configure your application: Use the provided SMTP credentials to configure your email sending application or service. This will ensure that all test emails are sent through Mailtrap's servers, allowing you to monitor and analyze their deliverability.
  3. Analyze results: Once you have sent a few test emails, check the inbox within Mailtrap's dashboard for any issues related to PTR records or other potential problems affecting your email delivery rates.

By following these usage tips PTR records explained, you can ensure that your emails are delivered to the recipient's inbox and not sent to the spam folder. It is imperative to bear in mind that PTR records are a vital part of the email delivery procedure, so make certain to examine and incorporate them as necessary.

FAQs in Relation to PTR Record

The Importance of PTR Records for Email Deliverability

PTR records are crucial for email deliverability, as they authenticate the sender's identity and protect against spammers.

They also improve mail server reliability by ensuring proper routing of emails.

Without a properly configured PTR record, your emails may be marked as spam or not delivered at all.

An Example of a PTR Record

A typical PTR record looks like this: " IN PTR example.com."

In this case, the IP address points to the domain name "example.com."

This reverse DNS entry helps verify that the sending server's hostname matches its IP address.

Are PTR Records Deprecated?

No, PTR records are not deprecated; they remain essential for email deliverability and security purposes in today's internet landscape despite advancements in authentication technologies such as SPF, DKIM, and DMARC.

How to Check if Your PTR Record is Correct

You can check your current configuration using command-line tools like dig and nslookup.

Online resources such as MxToolbox Reverse Lookup can also be helpful.

If necessary, consult with EDIS Global Support Team to ensure accurate settings for optimal email delivery.


PTR Records are essential for email deliverability, verifying sender identity, preventing spam, and improving mail server reliability, and can be managed using tools like dig, nslookup, or MxToolbox.

Ensure each A-record has a corresponding PTR record.

Properly configured PTR records enhance analytical capabilities, prevent bounce backs, improve email security, and identify fraudulent domains used by spammers, making them a crucial component of any email strategy.