Configuring reverse DNS (rDNS) with multiple IP addresses involves creating distinct A and PTR records for each IP, ensuring each IP maps back to a unique hostname. This setup is crucial for email deliverability, as it verifies the sending server's legitimacy, builds trust with receiving mail servers, and prevents spoofing. Using dedicated IPs is essential, as shared IPs typically lack rDNS control. Including SPF TXT records for hostnames enhances security. Verify the EHLO value used by the sending machine. Avoid pointing multiple IPs to the same hostname.
9 marketer opinions
Configuring reverse DNS (rDNS) with multiple IP addresses is crucial for email deliverability. Each IP address must have a unique hostname, requiring separate A and PTR records. This setup helps verify the sending IP's association with a legitimate domain, building trust with receiving mail servers and preventing email spoofing. It's generally advised to avoid pointing multiple IPs to a single hostname.
Marketer view
Email marketer from ServerFault responds by advising to avoid having multiple IPs pointing to a single hostname, because email servers validate rDNS to protect from spam.
3 Apr 2024 - ServerFault
Marketer view
Email marketer from DNS Records shares that to setup rDNS, create an A record that links your domain name to your IP address. Then, use your DNS management to create a PTR record pointing your IP address to the domain name.
2 Sep 2023 - DNS Records
6 expert opinions
Configuring reverse DNS (rDNS) with multiple IP addresses involves setting up individual hostnames for each IP, which aids in email delivery. Using dedicated IPs is crucial, as shared IPs typically don't allow rDNS control. It's important to ensure rDNS records align with the sending server's hostname, and including SPF TXT records for hostnames can enhance security. Verifying the EHLO value used by the sending machine in email headers is also recommended. A common approach involves creating hostnames such as `mta.yourdomain.com` and `mta2.yourdomain.com`.
Expert view
Expert from Email Geeks suggests setting up hostnames for each IP and using that hostname when publishing the rDNS.
29 Mar 2022 - Email Geeks
Expert view
Expert from Email Geeks shares that when they were at Salesforce, they would have used `mta.ml.hostname.com` and `mta2.ml.hostname.com` and suggests Mailgun will have to advise, but expects a similar setup would be appropriate.
9 Sep 2022 - Email Geeks
5 technical articles
Configuring reverse DNS (rDNS) with multiple IP addresses requires creating A records to map hostnames to IP addresses and PTR records to map IP addresses back to those hostnames. Each IP needs its own PTR record pointing to a unique hostname. This setup verifies the sender's identity during email communication, which is a crucial step in anti-spam measures.
Technical article
Documentation from Linode explains that reverse DNS maps an IP address back to a domain name. For multiple IPs, each IP needs its own PTR record pointing to a unique hostname.
4 Feb 2022 - Linode
Technical article
Documentation from RFC 1035 explains that PTR records are used in the domain name system to map an IP address to a name. This is especially relevant for email servers verifying sender identity through reverse DNS lookups.
25 Feb 2022 - RFC Editor
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