What is the impact of updating reverse DNS on an MTA and what are the best practices?
Summary
What email marketers say10Marketer opinions
Email marketer from SparkPost shares that setting up reverse DNS is a fundamental step in improving email deliverability. It helps validate the sending server's identity and reduces the likelihood of emails being marked as spam.
Email marketer from Email Geeks shares that ensuring the EHLO hostname/SPF entry matches is important, otherwise it may cause issues. They also expect that some places would assign reputation based on the hostname.
Email marketer from StackOverflow highlights the importance of maintaining consistent DNS records. The A record must match the hostname in the PTR record to prevent deliverability issues. Always verify that both records are correctly configured and point to the same values.
Email marketer from SendGrid explains that Reverse DNS (rDNS) can positively impact your IP reputation. Setting up rDNS helps ensure that your sending server is correctly associated with your domain, which increases trust with receiving mail servers.
Email marketer from WebHostingTalk Forum mentions that if you change your reverse DNS records, it can take up to 72 hours for the changes to propagate across the internet. During this time, some mail servers may not recognize the updated record, which could affect deliverability.
Email marketer from GMass explains that setting up rDNS properly means when a receiving mail server does a reverse lookup on your mail server's IP address, it will resolve to your domain name. This alignment is a signal that you're a legitimate sender.
Email marketer from Email Geeks shares that updating the reverse DNS shouldn't cause issues, but it's important to do it correctly the first time to avoid automated listings on RBLs due to feedback loops from filter providers. They also recommend manually checking for only one PTR record for the IP.
Email marketer from Mailjet emphasizes that reverse DNS is crucial for establishing trust with receiving mail servers. A properly configured PTR record confirms that the sending IP address is authorized to send emails for the domain, improving deliverability.
Email marketer from Reddit explains that reverse DNS is an essential part of email infrastructure. Without it, your emails are more likely to be flagged as spam. Make sure your sending IP has a valid PTR record pointing to your domain.
Email marketer from Email Geeks suggests considering the age and TLD of the new domain, as newer domains and gTLDs may cause issues.
What the experts say3Expert opinions
Expert from Word to the Wise explains that ensuring forward and reverse DNS records match is crucial. Inconsistent records may cause authentication failures, and email servers may not trust messages from such sources. Therefore, it's best practice to maintain identical records for A and PTR lookups.
Expert from Spam Resource responds that if your mail server doesn't have a PTR record, or the PTR record doesn't match the hostname used by the mail server, many receiving servers will reject your email or mark it as spam. A PTR record shows that the IP address has been legitimately assigned to a mail server.
Expert from Email Geeks explains that updating the reverse DNS should have little impact, advising to get it right to avoid issues.
What the documentation says4Technical articles
Documentation from DigitalOcean Community provides a detailed guide on configuring reverse DNS for a server. It advises ensuring the hostname matches the forward DNS record and that the PTR record points back to the correct hostname to avoid email delivery issues.
Documentation from Microsoft Learn explains that PTR records, also known as reverse DNS records, map an IP address to a hostname. Properly configured PTR records are crucial for email server reputation and deliverability, as they help verify the legitimacy of the sending server.
Documentation from Google Workspace Admin Help emphasizes the importance of accurate DNS records, including PTR records, for ensuring email delivery. It highlights that incorrect or missing PTR records can lead to emails being flagged as spam.
Documentation from RFC Editor explains that RFC 1035 specifies the implementation and specification of the Domain Name System (DNS). Although it doesn't directly address email, the document outlines PTR record requirements that are essential for reverse DNS lookups, which is crucial for email deliverability and authentication.