How do I perform a reverse DNS lookup and interpret the results?
Summary
What email marketers say8Marketer opinions
Marketer from Email Geeks shares a tool for looking up reverse DNS records, linking to `xnnd.com`.
Email marketer from StackOverflow shares that your server should have a fully qualified domain name (FQDN) and the reverse DNS should resolve to that same FQDN. This consistency is a key factor in passing spam filters.
Email marketer from Atech Media responds by explaining that a reverse DNS lookup helps confirm that the IP address is authorized to send emails for the domain. If the reverse DNS record matches the sending domain, it increases the trustworthiness of the email source.
Email marketer from WebHostingTalk Forums explains that a missing or incorrect reverse DNS record can severely impact email deliverability. Major email providers often use it as a factor in determining whether to accept or reject incoming emails.
Email marketer from Namecheap Support shares that reverse DNS lookups are important for verifying the identity of a server and helping prevent email spoofing. It helps mail servers confirm that an email is coming from a legitimate source.
Email marketer from Site24x7 states that having a properly configured reverse DNS helps mail servers verify the sender's identity and combat spam effectively. Without it, emails are more likely to be marked as spam or rejected outright.
Email marketer from Reddit explains that a correctly configured reverse DNS record is crucial for email authentication. Many mail servers will reject emails from servers without a valid reverse DNS record, as it's a common indicator of spam.
Email marketer from EasyDMARC explains that you can use online tools like their own reverse DNS lookup tool, or command-line tools like `dig` or `nslookup` to find the PTR record associated with an IP address.
What the experts say4Expert opinions
Expert from Email Geeks shares the command `dig -x IP.address.goes.here` to perform a reverse DNS lookup.
Expert from SpamResource.com explains that a properly configured reverse DNS record is vital for email deliverability. Many ISPs and email providers use reverse DNS to verify the authenticity of sending servers.
Expert from Email Geeks explains that in a reverse DNS record, the part that looks like a hostname is the reverse DNS of that IP address. They clarify that PTR is the same as rDNS. As an example 'In this record the IP address 104.225.223.157 has a reverseDNS of <http://mx.wordtothewise.com|mx.wordtothewise.com>'.
Expert from Word to the Wise shares that having a PTR record that matches your sending domain's reputation is critical for good delivery. Inconsistencies between the PTR record and the domain can negatively affect sender reputation.
What the documentation says5Technical articles
Documentation from Microsoft explains how to verify a reverse lookup zone and its resource records by using the `nslookup` command. The command will return the name associated with the IP address if the PTR record is configured correctly.
Documentation from RFC 1035 describes the PTR record as a pointer to a canonical name. In the context of reverse DNS, this canonical name is the domain name associated with an IP address.
Documentation from DigitalOcean explains that a reverse DNS record (PTR record) maps an IP address to a domain name. This is the opposite of a standard DNS A record, which maps a domain name to an IP address. It's important for email deliverability and server identification.
Documentation from Google Cloud explains that you can use the `dig` command with the `-x` option followed by the IP address to perform a reverse DNS lookup. The output will show the PTR record, which contains the hostname associated with the IP address.
Documentation from MXToolbox explains that the PTR record is used for reverse DNS lookups, which map IP addresses to domain names. This helps verify the legitimacy of the server sending the email and is used as a spam-fighting technique.