How does missing or different reverse DNS (rDNS) impact email deliverability, and when is a dedicated IP address needed?
Summary
What email marketers say11Marketer opinions
Email marketer from Mailjet shares that having a correct rDNS record is crucial for building a good sender reputation and improving email deliverability. An rDNS record that matches your sending domain helps ISPs confirm the legitimacy of your emails.
Email marketer from Reddit shares that getting a dedicated IP depends less on volume and more on reputation management. They suggest a dedicated IP is good if the sender can maintain a high sender score, otherwise, a shared IP with a reputable ESP is better.
Email marketer from Email Geeks advises to exclude concerns about rDNS when evaluating reasons for needing a dedicated IP address. As long as the IP doesn’t point nowhere, it should have little to do with deliverability. It is unlikely to rock the boat if you are not a perfectionist where Google does not expect perfection. States there's no upside to switching to a dedicated IP address because of anything discussed in this thread. Volume is about ~4Ok/month which is well within the scope of shared IP addresses.
Email marketer from Email Marketing Forum discusses that problems sending emails to particular email providers was solved when they corrected their rDNS record to match their sending domain. They share that their email open rate went up significantly
Email marketer from DigitalOcean details the need to set up rDNS for email servers. Reverse DNS helps receiving servers verify that the sending server is authorized to send emails for a particular domain, and without it, emails may be flagged as spam or rejected outright.
Email marketer from Constant Contact explains that poor RDNS setup can lead to emails being marked as spam and a damaged sender reputation. Ensuring your RDNS record matches your domain is key to proving the legitimacy of your emails.
Email marketer from ZeroBounce advises that a dedicated IP is beneficial for senders who can maintain a consistent sending volume and a clean email list. They state that without proper list hygiene, a dedicated IP can quickly become a liability.
Email marketer from SendPulse explains that a dedicated IP address is needed when sending a high volume of emails (50,000+ per month) or when wanting more control over sender reputation. They share that consistent sending practices and careful list management are essential for maintaining a good reputation on a dedicated IP.
Email marketer from SparkPost explains that if an IP address lacks a Reverse DNS (rDNS) record, receiving mail servers are more likely to consider emails from that IP as spam. A missing rDNS record makes it difficult to verify the legitimacy of the sending server and can negatively impact sender reputation.
Email marketer from ReturnPath (now Validity) shares that a dedicated IP is beneficial for senders who need more control over their reputation and want to isolate their sending from the activities of other senders on a shared IP.
Email marketer from Litmus emphasizes the need for a dedicated IP address when aiming for greater control over sender reputation. A dedicated IP allows you to manage and monitor your sending practices closely, which is essential for maintaining a positive sender score.
What the experts say4Expert opinions
Expert from Email Geeks advises not to assume that all IPs in a range are used for sending mail. States that there are a lot of pools that aren’t the whole /24. They state that rDNS only matters if mail is seen from the IP.
Expert from Word to the Wise explains the importance of reverse DNS for email deliverability, stating that many ISPs use it as a factor in determining whether to accept or reject an email. They suggest that a missing or incorrect RDNS record can severely affect inbox placement.
Expert from Spam Resource explains that a correct reverse DNS (rDNS) record is a crucial part of email authentication and that failing to have a valid, matching rDNS record will significantly reduce email deliverability. A dedicated IP address might be considered when a sender requires full control over their sending reputation and volume.
Expert from Email Geeks explains that missing reverse DNS may impact delivery, especially for enterprise filters. They clarify that Yahoo and Google require round trip DNS. Different reverse DNS across a range isn’t a problem in itself.
What the documentation says4Technical articles
Documentation from Microsoft Learn explains that a missing or incorrect Reverse DNS (rDNS) record can negatively impact email deliverability as many email servers use rDNS to verify the identity of the sending server. If the rDNS record doesn't match the sending IP address, the email might be flagged as spam.
Documentation from Google Workspace Admin Help shares that Google recommends using a dedicated IP if sending over 5,000 emails per day. They specify that this volume warrants the investment in managing and monitoring your own IP reputation to ensure consistent deliverability to Gmail users.
Documentation from RFC Editor details standard DNS configuration, emphasizing the importance of PTR records (rDNS) for reverse lookups. It explains that failing to have a proper rDNS record can lead to email being rejected by receiving mail servers that perform reverse DNS verification.
Documentation from Postfix.org highlights that proper rDNS configuration is a basic requirement for email authentication and deliverability. They state that servers without correctly configured rDNS are often viewed as less trustworthy and may face delivery issues.