Email Sending Reputation 101: IP Reputation vs. Domain Reputation

Email Sending 101: IP Reputation vs. Domain Reputation | Twilio SendGrid - 1
January 01, 2024
Written by
Jillian Smith
Opinions expressed by Twilio contributors are their own
Reviewed by
Ayanna Julien
Opinions expressed by Twilio contributors are their own
Denis O'Sullivan
Opinions expressed by Twilio contributors are their own

Email Sending Reputation 101: IP Reputation vs. Domain Reputation

Many factors influence email deliverability, with two key elements being your IP reputation and domain reputation. Others include sender authentication, keeping clean email lists, sending wanted content, having a good sending reputation, and much more.

Your sending reputation is how inbox service providers (ISPs) identify you as a legitimate sender. So every time you send an email campaign, ISPs collect valuable data that says whether you follow proper sending practices.

There are 2 types of email reputation: internet protocol (IP) reputation and domain reputation. Let’s look at the difference between them and why you need to pay attention to each.

What is IP reputation?

All emails come from IP addresses, which serve as unique identifiers of email streams. This means that part of your email reputation will be your IP reputation. 

Some companies send from a shared IP, which means multiple companies use the same IP address to send email. However, senders with higher email sending volume usually opt to send from a dedicated IP address that belongs only to them. 

But no matter what your sending volume is, email senders should send their transactional and marketing emails from separate IP addresses. This is crucial to maintain good deliverability for your transactional emails.

Check out Shared and Dedicated IPs: Which Should You Choose? to learn more about the differences between shared and dedicated IPs.

It’s critical for your IP reputation to warm up the IP properly before sending to your entire list.

If you send your email from a dedicated IP address, it’s critical for your IP reputation to warm up the IP properly before sending to your entire list. Check out Twilio SendGrid’s Email Guide for IP Warm Up for best practices to ensure you’ve set up and prepared your IP for your sending needs and have the best foundation for strong IP reputation and email reputation.

What is domain reputation?

Your domain reputation centers on your sending domain. This means that your branded website takes precedence when it comes to ISP filtering decisions.

Some inbox providers will put more emphasis on your domain reputation vs. your IP reputation, although many will look at both your IP and domain reputation when making decisions about whether or not your mail will make the inbox.

Domain authority

Domain authority, closely linked to domain reputation, refers to the overall strength or influence of your website in terms of how it ranks on search engine results pages. And while the connection between this and email marketing may not be immediately obvious, inbox providers can weigh this into their decision into whether or not you are a legitimate sender.

Portable reputation

The idea of portable reputation appeals to senders who want the flexibility to add new IPs, move IPs, or change email service providers (ESPs) without losing the good email reputation they’ve already built from their sending activity.

IP reputation vs. domain reputation: what's the difference?

After exploring the individual concepts of IP reputation and domain reputation, it's important to understand how they differ and interact in the context of email deliverability. Both are critical, but they function in distinct ways.

IP Reputation:

  • Focused on the Source: IP reputation is tied to the specific IP address from which emails are sent. It’s a measure of the trustworthiness of emails originating from that IP.
  • Influenced by Volume and Behavior: High volumes of email, especially if they trigger spam complaints or are marked as junk, can negatively impact IP reputation. Consistently good practices, however, enhance it.
  • Shared vs. Dedicated Impact: On a shared IP, your reputation can be influenced by the actions of others using the same IP. With a dedicated IP, you have full control over the reputation tied to that address.

Domain Reputation:

  • Focused on the Brand: Domain reputation is linked to your sending domain (your brand's URL). It reflects the credibility of emails associated with your domain.
  • Relates to Content and Engagement: This reputation is influenced more by the quality of the content, engagement rates, and how recipients interact with your emails (like open rates and forwarding).
  • Long-term and Portable: Domain reputation builds over a longer period and is not tied to a specific IP address, making it portable if you change email service providers.

Key Differences:

  1. Scope of Impact: IP reputation is about the sending address's behavior, while domain reputation is about the brand’s overall email practices.
  2. Control: You have more control over your IP reputation, especially with a dedicated IP. Domain reputation, however, is influenced by factors beyond just sending practices, like recipient interaction.
  3. Longevity and Portability: Domain reputation is more enduring and follows your domain regardless of IP changes, while IP reputation is specific to an individual IP address and needs to be built up when the IP changes.

Both IP and domain reputations are pivotal in determining email deliverability. While IP reputation can be seen as a short-term indicator heavily influenced by recent sending behaviors, domain reputation is a long-term indicator reflecting the overall trust in your brand's communication. Understanding and nurturing both reputations is essential for a successful email marketing strategy.

    Check your email reputation with Twilio SendGrid

    If you’re wondering how to check your email reputation, there are several options available

    • Sender Score
    • Microsoft SNDS
    • Google Postmaster Tools 

    Since there’s no singular standard, it’s best to use several tools combined to gain full visibility into how ISPs might view and treat your messages—that’s where we come in.

    Improve your email reputation with Twilio SendGrid. We’ll give you the best email sending practices to help you avoid common mistakes and preserve excellent sender reputation.

    To learn more about sending reputation and tips to stay in compliance with ISPs, download our 2020 Email Deliverability Guide.

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