Understanding rDNS: What It Is and Why It Matters for Email Deliverability

Reverse DNS (rDNS) might sound technical, but if you’re sending emails, understanding it is crucial. Whether you're using a platform like Mailforge or Infraforge, getting rDNS configuration right directly impacts your email deliverability and sender reputation. Let’s break it all down!

What Is rDNS and What Does It Do?

Reverse DNS (rDNS) is the opposite of DNS (Domain Name System). While DNS resolves a domain name into an IP address (e.g., "example.com" → "192.168.1.1"), rDNS resolves an IP address back to a domain name.

For example:

• DNS lookup: "mail.example.com" → "192.0.2.1"

• rDNS lookup: "192.0.2.1" → "mail.example.com"

When it comes to email, rDNS is a key authentication factor. It ensures that the IP address sending an email matches the domain it's associated with. If there’s no rDNS record or it doesn’t match, your emails might be flagged as spam or blocked outright.

rDNS in Action: Mailforge vs. Infraforge

Why rDNS Doesn’t Match on Mailforge

On Mailforge, rDNS mismatches can happen for a few reasons:

1. Shared IPs: Multiple users share the same IP, leading to mismatched or generic rDNS records.

2. Default provider settings: If the rDNS isn’t explicitly set, it might point to a generic hostname instead of your domain.

Why rDNS Matches on Infraforge

Infraforge ensures rDNS matches because of its robust infrastructure:

1. Dedicated IPs: Each user gets a dedicated IP, allowing precise rDNS configuration.

2. Core domain alignment: Infraforge aligns the core domain (the primary sending domain) with the IP’s rDNS, ensuring a seamless match.

3. Automated rDNS setup: Infraforge automates rDNS record configuration, minimizing errors and ensuring compliance with email best practices.

How rDNS Affects Deliverability

Having a properly configured rDNS is critical for email deliverability. Here’s how:

1. Spam Filter Checks: Mail servers often check the rDNS of incoming email. A mismatch or missing record is a red flag, increasing the chance of your emails being marked as spam.

2. Trust and Reputation: An accurate rDNS helps establish trust with recipient mail servers. It signals that your email infrastructure is legitimate and well-configured.

3. ISP Guidelines Compliance: Internet Service Providers (ISPs) often require rDNS to match for proper email delivery. Some ISPs outright reject emails from IPs without valid rDNS records.

The Role of Core Domains in Infraforge

What Is a Core Domain?

The core domain in Infraforge refers to the primary domain associated with your email-sending infrastructure. It’s the domain that aligns with your IP’s rDNS record and plays a critical role in reputation management.

How Core Domains Impact rDNS, Reputation, and Deliverability

1. rDNS Matching: Infraforge ties the core domain to the IP address’s rDNS, ensuring seamless alignment.

2. Improved Reputation: Consistency between the core domain and rDNS helps build a strong sender reputation. ISPs recognize this alignment as a sign of authenticity.

3. Enhanced Deliverability: With rDNS configured to match the core domain, your emails are more likely to land in inboxes rather than spam folders.

Key Takeaways for Your Email Infrastructure

1. Always Configure rDNS: Ensure your rDNS points to your sending domain.

2. Match IPs to Domains: Use dedicated IPs whenever possible to avoid rDNS mismatches.

3. Leverage Platforms Like Infraforge: Automating rDNS configuration and maintaining a consistent core domain are game-changers for deliverability.

By understanding and managing rDNS properly, you can significantly enhance your email-sending reputation and improve the chances of your emails reaching your audience.