The 8 Best Ways to Improve Your Email Sender Reputation

You’ve spent weeks crafting the perfect email campaign. It has a catchy subject line, compelling copy, and a valuable offer. You hit send, anxious for high open and click-through rates, only to find that most of your subscribers never even saw the email.

Why so many failed email sends? Most of your emails either ended up in spam folders or worse, never reached your audience.

The most likely culprit for this communication calamity is a poor sender reputation.

Your email sender reputation is the unseen gatekeeper determining whether your emails land in inboxes or vanish into digital oblivion. Understanding and managing email sender reputation is essential to maximize deliverability and engagement.

In this guide, we’ll explore everything you need to know about email sender reputation and equip you with actionable strategies to improve yours.

Contents

• What is email sender reputation?
• How are email sender reputations scored?
• Why does email sender reputation matter?
• 8 factors that influence sender reputation and how to control them

What is an email sender reputation?

Email sender reputation is a metric that determines how trustworthy an email—and the account that sent it—is. It reflects how internet service providers (ISPs) view your emails and whether they think your recipients want to see them.

An email sender reputation is like a credit score but for email marketing. ISPs and email providers are like the credit providers. They review your reputation (or score) to decide whether you’re a risk or not. Then, instead of approving a loan, ISPs decide if your email gets blocked, gets labeled as spam, or makes it to the receiver’s inbox. Just like a credit score, the higher your reputation, the more likely you are to have success.

How email sender reputations are scored

The scale used to express an email sender reputation depends on the scoring system used by monitoring tools. Here are some common examples:

1. Google Postmaster Tools use a non-numerical range:
   • Bad: Likely to have deliverability issues.
   • Low: At risk but not critical.
   • Medium: Average reputation.
   • High: Strong reputation with minimal deliverability concerns.
2. Microsoft SNDS (Smart Network Data Services) works similarly to Google Postmaster Tools, with qualitative insights rather than exact numbers.
3. Talos Intelligence (Cisco) uses a numerical range of -10 (very poor) to +10 (excellent), with neutral at 0.

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Why does email sender reputation matter?

Email sender reputation directly influences whether your emails reach their intended audience or are sidelined as spam. A strong reputation ensures better deliverability and engagement. Your sender reputation:

• Determines inbox placement: A high reputation means more emails get to their intended inboxes. Low reputation means emails going to spam folders and never being seen.
• Impacts engagement metrics: A good reputation leads to higher inbox placement, which drives more opens, clicks, and conversions.
• Protects brand credibility: A poor reputation, signaled by spammy emails or frequent complaints, damages trust and risks alienating your audience.
• Drives ROI for email campaigns: A strong sender reputation gets you higher deliverability rates, and every percentage point in deliverability translates to better campaign performance and profitability.
• Avoids an email embargo: If your reputation falls too low, you risk being embargoed by ISPs or spam-monitoring organizations. A higher reputation keeps you out of this nefarious club.

Email sender reputation impacts deliverability, engagement, brand trust, ROI, and your ability to avoid serious consequences like blacklisting. By prioritizing reputation management, you can make sure your emails consistently reach and resonate with your audience.

8 factors that influence email sender reputation and how to control them

Eight key factors shape your email sender reputation. Collectively, they signal to ISPs whether your emails are trustworthy and relevant. The good news is these factors are within your control, and you can manage them to improve your sender reputation.

1. Bounce rates

Bounce rates are the percentage of emails that fail to deliver, typically due to invalid, inactive, or non-existent addresses. A high bounce rate signals poor list hygiene.

ISPs interpret frequent bounces as a sign you’re not maintaining a quality email list, which can lower your reputation. If you have a high bounce rate, you should:

• Regularly clean your email list to remove invalid or inactive addresses: Use email validation tools like NeverBounce or ZeroBounce to identify and remove addresses that are no longer valid or active.
• Implement double opt-in for new subscribers: Ensure that only valid and interested people are added to your list by requiring subscribers to confirm their email addresses before they are fully added.
• Monitor and update email collection methods: Evaluate how you collect email addresses to ensure accuracy, such as using registration form validation to prevent typos and capturing only verified, high-quality leads.

2. Spam complaints

Spam complaints are the number of times recipients mark your emails as spam. When recipients mark your emails as spam, it’s a red flag for ISPs that your content is unwelcome. High complaint rates quickly erode your sender reputation and lead to lower deliverability.

• Set clear expectations during signup: Clearly communicate what type of content subscribers will receive, how often you’ll email them, and any additional benefits.
• Monitor and suppress unengaged recipients: Regularly review engagement metrics and remove or suppress subscribers who haven’t interacted with your emails for a long time.
• Use clear opt-in methods: Ensure that everyone on your email list has explicitly agreed to receive your emails.

3. Recipient engagement

Recipient engagement is a measure of how recipients interact with your emails, including actions like opening, clicking, and reading. Engagement metrics like open rates, click-through rates, and time spent on emails reflect how interested recipients are in your content.

Low engagement suggests to ISPs that your emails lack value, which leads to inbox placement issues. To address this issue:

• Personalize your emails: Tailor your content by using recipient data such as names, past interactions, or preferences. Personalized emails make recipients feel valued and increase the likelihood of engagement, which signals ISPs that your emails are relevant.
• Segment your audience: Group your email list into smaller, targeted segments based on factors like demographics, purchase history, or behavior. Sending specific content to the right audience increases relevance and improves metrics like open and click-through rates.
• Optimize your email timing: Analyze when your audience is most likely to engage with emails and schedule sends accordingly. Tools like email marketing platforms can provide insights into optimal send times based on past performance.
• Create mobile-friendly emails: Many recipients open emails on mobile devices, so ensure your emails are optimized for smaller screens with responsive designs, clear fonts, and concise messaging. A poor mobile experience can lead to disengagement.

Segmenting your email list by geography is a great way to send more relevant messages to each subscriber.

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4. Sending practices

Sending practices refer to the consistency and quality of your email-sending behavior, such as maintaining a steady volume and avoiding unverified lists, which impacts ISP trust.

ISPs monitor the consistency and legitimacy of your email-sending patterns. Sudden spikes in email volume or sending to purchased lists can raise red flags, harming your reputation.

Here are some ways to refine your email-sending practices:

• Maintain a consistent sending volume: Sudden spikes or drops in email volume can make ISPs suspicious of your activity. For example, sending thousands of emails after weeks of inactivity might trigger filters. Plan your campaigns to send emails at a steady and predictable pace to build trust over time.
• Avoid purchased or scraped lists: Using lists that haven’t been organically collected leads to higher bounce rates, spam complaints, and potential spam trap hits. Instead, grow your list through opt-ins, where recipients voluntarily subscribe to receive your emails.
• Warm up new IPs gradually: If you’re starting with a new IP address, don’t send large volumes of emails immediately. Begin with smaller sends to highly engaged recipients, gradually increasing the volume to establish a positive reputation with ISPs.
• Respect frequency preferences: Give recipients control over how often they receive emails from you. Sending too many emails can annoy subscribers and increase complaints, while too few might result in disengagement.

5. Authentication protocols

Authentication protocols are verification methods like SPF, DKIM, and DMARC that confirm your identity as a legitimate sender, reducing the risk of being flagged as spam. Here’s what each of these acronyms mean:

• SPF (Sender Policy Framework): An email authentication protocol that verifies whether a sender’s IP address is authorized to send emails on behalf of a domain.
• DKIM (DomainKeys Identified Mail): An email authentication method that uses cryptographic signatures to ensure the email’s content has not been altered during transit.
• DMARC (Domain-based Message Authentication, Reporting, and Conformance): A policy framework that builds on SPF and DKIM to help email senders and receivers prevent spoofing and phishing while providing visibility through reports.

Missing or misconfigured protocols make your emails appear suspicious and increase the likelihood of being flagged as spam.

Setting up SPF, DKIM, and DMARC improves email deliverability by ensuring your emails are authenticated and trusted by ISPs. These protocols protect your domain from spoofing and phishing attacks, enhance sender reputation by demonstrating compliance with authentication standards, and reduce the likelihood of being flagged as spam.

Additionally, DMARC provides valuable insights into email activity through detailed reports, helping you monitor and fine-tune your email strategy for better performance.

Here’s how to set up each protocol.

Sender Policy Framework (SPF)

Log in to your domain registrar or hosting provider to manage DNS records. Then, add a TXT record to your domain’s DNS with the following format:

makefilev=spf1

include:example.com ~all

• Replace example.com with the email service providers you use (e.g., Gmail, SendGrid).
• Use ~all for soft fail (recommended for testing) or -all for hard fail (stricter enforcement).

After that, save changes to your DNS. Propagation may take a few hours. As a final step, use tools like MXToolbox or SPF Record Checker to verify the setup.

DomainKeys Identified Mail (DKIM)

Most email providers (e.g., Gmail, SendGrid) offer a DKIM key in their account settings. Go to account settings and generate a DKIM key. After that, add a TXT record with the selector and public key provided by your email provider.

Here’s an example of how that looks:

vbnet

Name: selector._domainkey.example.com

Value: v=DKIM1; k=rsa; p=<public key>

Once the TXT record is added in your email provider’s settings, enable DKIM signing for outgoing emails. Use email testing tools or your email provider’s verification tool to confirm the DKIM signature is applied correctly. Besides MX Toolbox, Mail Tester is also a good tool to test this.

Domain-Based Message Authentication, Reporting, and Conformance (DMARC)

Decide on your policy (monitoring, quarantine, or reject). For example:

css

v=DMARC1; p=none; rua=mailto:[email protected]

• p=none: Monitor and gather data.
• p=quarantine: Mark unauthorized emails as spam.
• p=reject: Block unauthorized emails outright.

After that, add a TXT record to your DNS with the DMARC policy, like this example:

css

Name: _dmarc.example.com

Value: v=DMARC1; p=quarantine; rua=mailto:[email protected]

Start with p=none to monitor activity, then move to stricter policies (quarantine or reject) as your setup stabilizes. Use a DMARC reporting tool like DMARCian or Agari to analyze authentication reports and fine-tune your policy.

6. Spam trap hits

Spam traps are email addresses intentionally created by ISPs and anti-spam organizations to identify senders who are using poor list management practices. Real people do not use these addresses and never sign up for email lists, so if your email lands in a spam trap, it signals that you may be sending to unverified or outdated addresses. Spam trap hits can severely damage your sender reputation.

If you use double opt-ins for email signups and regularly clean your email list, your chances of landing in a spam trap are already low. In addition to that, make sure you:

• Avoid purchased or scraped lists: Purchased or scraped email lists often contain spam traps. Always build your email lists organically through legitimate signup processes.
• Monitor engagement metrics: Keep an eye on recipient engagement (opens, clicks, etc.). If certain segments show no activity, suppress or remove them from your list to reduce the risk of hitting a trap.
• Conduct regular audits: Periodically review your list management practices and audit your email database to ensure compliance with industry standards. Besides the tools we have already recommended, Kickbox and Debounce can also help you with your audits.

7. Content quality

Content quality refers to the relevance, clarity, and value of the emails you send to your audience. ISPs and spam filters analyze your content to determine whether it meets recipients’ expectations or if it resembles spam.

Poor-quality content, such as misleading subject lines, excessive promotional language, or irrelevant messaging, harms your email sender reputation and reduces deliverability.

To ensure high-quality email content, follow these best practices:

• Craft clear and honest subject lines: Avoid clickbait or deceptive language in your subject lines. Use wording that accurately reflects the content of the email.
• Avoid spammy keywords and phrases: Words like “free,” “guaranteed,” and “act now” can trigger spam filters if overused. Promotional emails are okay; just keep your language professional and relevant to your audience.
• Provide value in every email: Deliver content that aligns with your recipients’ interests and needs, such as helpful tips, exclusive offers, or personalized recommendations.
• Test and optimize your emails: Use A/B testing to experiment with different subject lines, layouts, and content formats. Analyze the results to refine your approach and consistently improve the quality of your emails.

Timely, targeted emails with clear subject lines and valuable content will leave you with a strong email sender reputation.

8. Domain and IP reputation

Domain and IP reputation reflect the trustworthiness of your sending domain and the IP address used to send emails. ISPs evaluate these reputations to decide whether your emails are delivered, flagged as spam, or blocked entirely. Poor practices or shared IP issues degrade your reputation.

To build and protect a strong domain and IP reputation:

• Start slow and build up: When starting with a new IP, send emails in small batches to your most engaged recipients. Gradually increase the volume over time to establish a positive sending history and avoid ISP suspicion.
• Avoid sending from shared IPs (if possible): On shared IPs, other senders’ poor practices can affect your reputation. Use a dedicated IP if your email volume is high enough to justify it.

Take charge of your email sender reputation

Email sender reputation isn’t static; it evolves with every email you send. By addressing the eight factors that influence reputation, you’re not just fixing immediate problems but building a long-term strategy for trust and consistency.

Controlling these eight factors can serve as your blueprint for effective email marketing. Every step, from avoiding spam traps to warming up new IPs, contributes to a cohesive system that ensures your emails reach their audience.

Review your current practices, run audits, and start small by implementing one improvement today. By prioritizing these practices, you’ll create a system that amplifies your impact and makes sure your messages reach and resonate with your audience.

Here’s a recap of the eight factors that influence your email sender reputation:

• Bounce rates
• Spam complaints
• Recipient engagement
• Sending practices
• Authentication protocals
• Spam trap hits
• Content quality
• Domain and IP reputation