IP Reputation vs. Domain Reputation: Guide for Email Senders

Email Sending Reputation 101: IP Reputation vs. Domain Reputation

IP reputation and domain reputation are the dynamic duo of email deliverability, except one's got trust issues and the other has commitment problems.

Most email senders obsess over IP reputation like it's the only thing that matters.

Spoiler alert: it's not.

Modern inbox providers are increasingly putting domain reputation in the driver's seat, sometimes caring more about your domain than your IP address. 

The difference between IP reputation and domain reputation is a bit nuanced. One's a fling, the other's a relationship. Your IP reputation is relatively easy to rebuild if things go sideways (think 2-4 weeks of good behavior). But domain reputation—yeah, that follows you everywhere across email platforms, IP changes, and even that regrettable decision to switch providers.

Get either one wrong, and you've just bought yourself a first-class ticket to spam folder purgatory, where emails go to die and ROI goes to weep quietly in a corner.

This guide breaks down everything you need to know about IP reputation and domain reputation: how they actually work (it's more interesting than you think), how to keep tabs on them without becoming a monitoring obsessive, and how to optimize both so your emails land where they belong...in actual inboxes.

What is IP reputation?

IP reputation is the trust score assigned to your sending IP address based on your email sending behavior. It's tied to the specific internet protocol address your emails originate from.

Key IP reputation factors:

• Send volume consistency
• Bounce rate percentages
• Spam complaint ratios
• Authentication pass rates
• Engagement metrics (opens, clicks)
• Blacklist appearances

IP reputation scores typically range from 0-100, with scores above 80 considered good, and scores below 70 indicating deliverability problems.

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.

What is domain reputation?

Domain reputation focuses on your sending domain rather than your IP address. This makes domain reputation "portable"—it follows you when you change email service providers or IP addresses.

Key domain reputation factors:

• Domain age and history
• Website authority and traffic
• DMARC policy compliance
• DKIM signature consistency
• Subdomain vs. root domain usage
• Cross-channel reputation signals

Domain reputation is increasingly important as ISPs like Gmail and Yahoo prioritize domain-based filtering over IP reputation alone.

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: the major differences

Honestly, this isn't a question of which one is more important. They both matter. Period.

But they are different, and that's worth digging deeper into.

• Think of IP reputation as your short-term rental: you can move out, get a new place, and start fresh relatively quickly. 
• Domain reputation is your permanent address: It follows you everywhere, takes forever to change, and everyone knows where to find you.

The kicker is that different email providers treat these two very differently. Some are team IP, others have gone full domain-obsessed, and a few are still trying to figure out which one they like better. 

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.