Email Deliverability 101: How to Avoid the Spam Folder and Improve Inbox Placement

Unlock the secrets to high email deliverability. Learn how to bypass spam filters, optimize sender reputation, and ensure your emails reach their destination.

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Imagine sending out a perfectly crafted email campaign that never reaches your subscribers’ inboxes.

Frustrating, right?

That’s where understanding email deliverability and implementing strategies to boost your inbox placement comes in.

This guide uncovers the secrets to achieving high email deliverability rates and ensuring your well-designed emails reach the intended recipients.

Understanding Email Deliverability

Email deliverability is like a game of chess between your email marketing campaigns and the intricate algorithms of Internet Service Providers (ISPs).

Your sender reputation, email content, and authentication all come into play as ISPs decide which emails make the cut and which get lost in the abyss of spam folders.

Why is this significant for your email campaigns? A higher rate of email deliverability can result in increased email engagement, ultimately driving traffic, sales, or, at the very least, a reply, which is the ultimate goal of any email marketing campaign.

Like the importance of cultivating trust and reputation in the physical world, fostering a strong sender reputation in email marketing is essential.

ISPs and mailbox providers analyze factors such as your subject lines, email content, and sender reputation to determine whether your emails are considered legitimate or potential spam.

Therefore, understanding the role of ISPs and the significance of sender reputation in the email deliverability process is central to ensuring your emails reach their intended recipient’s inbox.

The Role of Internet Service Providers (ISPs)

ISPs act as the gatekeepers of the digital world. As far as emails go, they filter and classify emails based on various criteria, such as:

  • Sender reputation
  • Email content
  • Authentication protocols like SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance)

But what does this mean for email marketers and salespeople? It means that your email infrastructure, which includes your IP address, email authentication, and even the content of your emails, has a significant bearing on your email deliverability.

Sender Reputation Illustration

Improving your sender reputation, ensuring your emails are seen as legitimate, and boosting your email deliverability rates are all possible once you understand the role of ISPs in the email deliverability process and implement the proper authentication protocols.

The Importance of Sender Reputation

A good sender reputation is like a golden ticket in email marketing, as it influences ISPs’ decisions on delivering emails to recipients’ inboxes or spam folders.

Factors contributing to sender reputation include high unsubscribe rates, users marking emails as spam, and sending emails to spam traps. In other words, a strong sender reputation is essential for achieving high email deliverability rates.

While maintaining a good sender reputation may seem overwhelming, there’s no need to worry! Enhancing your sender reputation can be achieved by:

  • Crafting compelling emails with satisfactory click-through rates
  • Avoiding sending emails to spam traps
  • Being prudent with the amount and frequency of sending to avoid having your emails marked as spam due to over-sending

Keeping brand coherence in email campaigns is also pivotal, guaranteeing that customers recognize your brand and do not flag your emails as spam.

Key Factors Influencing Email Deliverability

Several key factors influence email deliverability, including authentication protocols, content quality and relevance, and list hygiene and engagement.

Your email deliverability rates can be significantly improved by implementing email authentication protocols, creating high-quality and relevant content, and maintaining good email hygiene and engagement practices.

Authentication Protocols

Authentication protocols are like digital passports for your emails. They verify the sender’s identity and guarantee that the email originates from a valid source. Implementing email authentication protocols like SPF, DKIM, and DMARC helps ISPs and mail servers validate your emails, ensuring that they are legitimate and improving email deliverability rates.

Sender Policy Framework (SPF)

SPF prevents spammers from sending messages on behalf of your domain. Domain owners publish SPF records in their DNS (or Domain Name System). These records list the servers authorized to send emails on behalf of the domain.

When an email is received, the receiving mail server checks the SPF record to verify that the email is coming from a server allowed by the domain’s SPF record.

However, SPF alone doesn’t ensure that the display name is protected. It only verifies the return-path domain, is used for email bounce messages, and is not typically visible to end-users.

DomainKeys Identified Mail (DKIM)

DKIM ensures that an email message was not tampered with during transit. It uses a pair of keys, one private and one public, to verify the message.

The sending server signs the message with a private key, and the receiving server uses the corresponding public key, published in the domain’s DNS, to verify the signature.

While DKIM verifies that the content of the email remains unchanged, it doesn’t specify any actions to be taken if a message fails the DKIM check.

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

DMARC builds upon SPF and DKIM. It allows domain owners to specify how an email should be handled if it fails SPF or DKIM checks.

DMARC policies are published in the domain’s DNS records. These policies specify how the receiving mail server should handle emails that don’t pass SPF or DKIM checks (e.g., reject the message, mark it as spam, or do nothing).

DMARC also includes a reporting feature that sends reports to the sender about messages that pass and/or fail DMARC evaluation. This helps organizations identify and address authentication issues.

Proper setup of these authentication protocols enables you to protect your domain from being spoofed by spammers, maintain a strong sender reputation, and improve your email deliverability in the long run.

Content Quality and Relevance

In email marketing, content is king. High-quality, relevant content is crucial for maintaining good email deliverability rates, as it:

  • Increases subscriber engagement
  • Reduces the likelihood of being marked as spam ISPs, ESPs, and spam filters evaluate your email messages based on:
  • Language used
  • Links contained in the message
  • Content length
  • Create engaging, relevant content that resonates with your subscribers
  • Avoid spam trigger words
Email Deliverability - Spam Trigger Words

Moreover, ensuring that your email designs are mobile-friendly is crucial for keeping your subscribers engaged and preventing your emails from landing in spam folders.

Focusing on content quality and relevance can help build trust with your subscribers, improve your sender reputation, and in turn, boost your email deliverability rates.

List Hygiene and Engagement

Adhering to good list hygiene and engagement practices ensures that your emails are successfully delivered to the intended inboxes, which is one of the most basic things you need to do to succeed with email deliverability.

This includes regularly updating and cleaning your email lists and monitoring subscriber engagement to identify and remove inactive subscribers and invalid email addresses.

Sending emails to invalid email addresses, role-based email addresses, and unengaged subscribers can detrimentally affect your sender reputation and reduce the likelihood of your emails being successfully delivered to the recipient’s inbox.

As with all aspects of email marketing, prioritizing data quality is key.

Strategies for Improving Email Deliverability

Now that we’ve covered the key factors influencing email deliverability, it’s time to put that knowledge into action.

This section will provide actionable strategies for improving your email deliverability rates. These strategies include optimizing your email infrastructure, personalizing and segmenting your email campaigns, and avoiding spam traps and complaints.

1. Optimize Your Email Infrastructure

Your email infrastructure is like the foundation of your email marketing efforts. Selecting the right email infrastructure, such as a dedicated IP address or shared IP address, can significantly impact your email deliverability rates.

Dedicated IP addresses are used by a single sender, while multiple senders utilize shared IP addresses. Your choice of IP address type can affect your sender reputation and, ultimately, your email deliverability success.

Additionally, complying with email authentication protocols, such as SPF, DKIM, and DMARC which we mentioned before, is crucial for maintaining a strong sender reputation and ensuring that your emails are delivered to your subscribers’ inboxes.

2. Personalize and Segment Your Audience

Personalization and segmentation are like the secret sauce of successful email marketing campaigns. Improving subscriber engagement and increasing your email deliverability rates can be achieved by personalizing and segmenting your email campaigns.

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Personalization involves tailoring your emails to target specific audiences. At the same time, segmentation is dividing your email list into smaller, more targeted groups based on demographics, behavior, and preferences.

Implementing personalization and segmentation strategies helps improve your email deliverability rates and creates a more engaging and relevant experience for your subscribers, encouraging them to interact with your emails and take desired actions.

All in all, you should be shooting for the following benchmarks:

Email Deliverability - Metrics

Ensuring that your emails remain relevant and engaging leads to higher email deliverability rates and overall campaign success.

3. Avoid Spam Traps and Complaints

Spam traps and complaints are like landmines in the email marketing landscape. Steering clear of spam traps and minimizing spam complaints can help maintain a strong sender reputation and improve email deliverability.

Spam traps are fake email addresses created by ISPs and blacklist providers to identify email marketers who have been collecting emails without permission, which can lead to their emails landing in the dreaded spam folder.

Sending emails to spam traps can negatively affect your sender reputation and reduce email deliverability. To avoid spam traps and minimize spam complaints, it is important to follow email marketing best practices, including:

  1. Regularly reviewing and verifying your email lists
  2. Use an email spam checker
  3. Implementing double opt-in to ensure that subscribers have explicitly consented to receive your emails
  4. Ensuring that your emails are engaging and relevant to your subscribers

Essential Email Deliverability Tools

In the quest for high email deliverability rates, having the right tools in your arsenal is essential. This section will highlight the importance of using email deliverability tools for monitoring sender reputation, testing email content and design, and analyzing email performance metrics.

These tools can provide valuable insights into your email marketing efforts and help you identify areas for improvement, ensuring that your emails are optimized for deliverability and engagement.

Email Sender Reputation Tools

Monitoring your sender reputation is like checking your credit score — it’s essential for maintaining trust and credibility with ISPs and ensuring that your emails reach their intended recipients.

Tools like Google Postmaster and Microsoft SNDS can help you monitor and maintain a strong sender reputation, which is crucial for high email deliverability rates.

These tools provide insights into your email traffic, delivery, and reputation, allowing you to identify potential issues and take corrective action to improve your sender reputation.

Regularly monitoring your sender reputation and making necessary adjustments can help ensure your emails are successfully delivered to your subscribers’ inboxes.

A/B Email Testing Tools

Testing your email content and design is like test-driving a car before you buy it. You want to ensure everything works perfectly and looks great before you hit the road (or, in this case, launch a full-scale campaign).

A/B testing involves sending two email versions to your audience and gathering data on which one performs best. Then, you can change your overall campaign before you launch it for a wider audience.

A/B Testing - Email Deliverability

Utilizing A/B email testing tools to do this is required, as most native email tools (like Gmail, etc) do not support it.

Some of the most recommended email testing tools for content and design include HubSpot and Mailchimp.

These tools allow you to test your emails in various email clients, verify if your emails may end up in the spam folder, and even test subject lines for optimal performance.

Regular testing of your email content and design can ensure that your emails are both visually appealing and effective in reaching your subscribers’ inboxes.

Email Analytics Tools

Regularly analyzing email performance metrics, such as open rates and click-through rates, can help you identify areas for improvement, optimize your email campaigns, and ultimately enhance overall campaign success.

Any tool you use to send your emails should also provide an analytics dashboard. If they don’t, look for another tool ASAP. Make sure it includes metrics like:

  • Delivery Rate: This is the percentage of emails that successfully reach the recipient’s inbox. A high delivery rate is crucial for ensuring your emails are not being blocked or sent to spam.
  • Bounce Rate: This metric tracks the number of emails that were not delivered successfully. Bounces can be hard (permanent failures like invalid addresses) or soft (temporary issues like a full inbox).
  • Open Rate: The open rate measures how many recipients are opening the emails you send. This can give insights into how engaging your subject lines and content are.
  • Click-Through Rate (CTR): This measures how many recipients clicked on a link within your email. It’s a key indicator of the effectiveness of your email content and calls to action.
  • Spam Complaints: Tracks how often your emails are marked as spam by recipients. High spam complaint rates can negatively impact your sender reputation.
  • Unsubscribe Rate: This is the rate at which people are opting out of your email list. It can indicate the relevance and quality of your email content.
What Is Email Deliverability? Breadcrumbs Cadence

Making data-driven decisions to improve your email deliverability and achieve your email marketing goals can be achieved by regularly monitoring and analyzing these metrics.

Tips for Maintaining High Email Deliverability Rates

Now that we’ve explored the key factors, strategies, and tools for improving email deliverability, we will now examine some practical tips for maintaining high email deliverability rates.

Regularly Review and Update Email Lists

Maintaining high deliverability rates and ensuring that your emails reach the inboxes of engaged subscribers isn’t as hard as a lot of folks make it out to be.

In reality, all the tips and tricks shared by ‘guru’s on LinkedIn are all basic maintenance tips that should be followed by all marketers and salespeople today.

To enhance your email list health, it’s essential to:

  • Identify disengaged subscribers and remove them from your list
  • Use email verification services to identify and remove invalid addresses and spam traps
  • Segment your list to ensure that you’re sending relevant content to your subscribers

Just like with any spring cleaning, maintenance can go a long way to helping you maintain or improve your deliverability rates.

Keeping up-to-date with email marketing trends and regulations can be tough, especially since the introduction of GDPR and other privacy regulations.

Some of the current regulations impacting email marketing and deliverability include:

While reading legalese all day might not be your cup of tea, generating thousands of dollars in fines over an easily preventable policy error surely isn’t.

Monitor and Adjust Email Strategies

Continuously monitoring and adjusting your email strategies is like fine-tuning a musical instrument. You must make small adjustments and tweaks to keep everything in harmony and perform optimally.

Some of the strategies you can implement to ‘tune-up’ email deliverability rates include:

  • Enhancing your sender score and reputation
  • Refraining from using spammy email content
  • Minimizing bounce rates
  • Authenticating your domain
  • Monitoring sender reputation and blacklists
  • Warming up your IP address
  • Utilizing a reliable email delivery service

By continuously monitoring your email performance and adjusting your strategies as needed, you can ensure the success of your email marketing campaigns.


In conclusion, mastering email deliverability is essential to successful email marketing campaigns.

By understanding the key factors influencing email deliverability, implementing effective strategies, and utilizing the right tools, you can significantly improve your email deliverability rates and achieve email marketing success.

Remember, maintaining high email deliverability rates is an ongoing process that requires continuous monitoring, adjustments, and a commitment to best practices.

By following the tips and strategies outlined in this blog post, you can stay ahead of the curve and ensure that your emails consistently reach your subscribers’ inboxes, driving engagement, conversions, and overall campaign success.

Frequently Asked Questions

What is email deliverability?

Email deliverability refers to the likelihood that emails sent are successfully delivered to a subscriber’s inbox, instead of being blocked or marked as spam. It is a metric used to measure the number of emails reaching recipients’ inboxes, and various strategies can be employed to improve its success rate.

How do I fix email deliverability?

In short, improve email deliverability, authenticate your email domain, maintain proper IP allocation, perfect the opt-in process, write non-spammy subject lines, provide a preference center, keep clean lists, avoid spam traps, and send emails people love.

What is a good email deliverability rate?

A good email delivery rate is 95% and higher, with a bounce rate no higher than 3% and a spam rate of no more than 0.03%.

What hurts email deliverability?

Some factors that negatively impact email deliverability are:

  • Poor Sender Reputation: ISPs judge your credibility based on your sender reputation. High bounce rates, spam complaints, and low engagement rates can harm your reputation.
  • Spam Complaints: If recipients frequently mark your emails as spam, this signals to ISPs that your content is not wanted, affecting deliverability.
  • High Bounce Rates: Many bounced emails (due to invalid, closed, or non-existent email addresses) can damage your sender reputation.
  • Lack of Email Authentication: Not using authentication protocols like SPF (Sender Policy Framework), DKIM (DomainKeys Identified Mail), and DMARC (Domain-based Message Authentication, Reporting & Conformance) can lead to delivery issues.
  • Frequent Sending to Inactive Addresses: Continually sending emails to inactive or unengaged subscribers can harm your reputation.
  • Spammy Content: Using language or formatting typical of spam (like excessive use of caps, exclamation marks, or spam trigger words).
  • Lack of Personalization and Segmentation: Sending the same content to all subscribers, regardless of their interests or behavior, can decrease engagement.
  • IP Address Reputation: Sharing an IP address with other senders who have poor practices can affect your own deliverability.
  • Not Including a Physical Address: Failing to include a physical mailing address can violate laws like CAN-SPAM, affecting deliverability.
  • Neglecting to Monitor Blacklists: Being on an email blacklist severely impacts deliverability, and it’s crucial to monitor and address any listings promptly.

What is the difference between a dedicated IP address and a shared IP address?

A dedicated IP address is exclusively used for a single sender, while a shared IP address is used by multiple senders. This can have a significant effect on your sender reputation and email deliverability.