Yotpo Email Deliverability Guide

What is email deliverability?

First, let's talk about email delivery vs. email deliverability.

Email delivery is about the technical ability to ensure your emails reach the correct inbox service provider, such as Google/Gmail, Microsoft/Hotmail, Yahoo, Apple/iCloud, etc. Meanwhile, email deliverability is the metric that measures the rate at which your emails reach your recipients’ inbox or promotions folders, rather than being delivered to spam.

Email delivery is completely in our control, and we’ve got you covered. Your emails will reach the inbox service provider, every time.

Email deliverability, on the other hand, is for the most part in your hands. The behaviors you exhibit as an email marketer will dictate whether your emails will reach the destination inbox, which is the ideal result, get diverted to the spam folder, or even get rejected by the inbox service provider altogether. Those behaviors affect the sender reputation that the inbox service providers assign to you, a sender score that ultimately determines your email deliverability behavior.

With that said, you must understand and adhere to the Email Marketing Deliverability Principles. This will boost your deliverability, which in turn will boost your open rates, click rates, and ultimately your conversion rates.

Check out our guide below to see everything you need to do to ensure your emails reach the inbox every time.  

Understanding Email Delivery Setup

Influencing Deliverability

Email deliverability depends on many factors, some you control, others influenced by mailbox providers and how recipients interact with your emails.

At the core, your domain and sending reputation, along with proper email authentication (SPF, DKIM, and DMARC), are essential for getting your emails into the inbox.

Content quality and list hygiene also play a big role. Send relevant, engaging emails to people who have clearly opted in. Avoid using purchased lists, generic messaging, or spammy language, as these can hurt your credibility.

Mailbox providers track engagement signals like open rates, clicks, spam complaints, bounces, and unsubscribes. High complaint or bounce rates often point to poor list quality or irrelevant messages, both of which can damage your reputation.

Your sending behavior matters too. Sudden spikes in volume or inconsistent sending (especially around holidays or sales) can raise red flags. Aim for a steady, predictable sending schedule to build trust with inbox providers.

Finally, don’t overlook technical and design issues. Broken links, slow-loading images, or missing unsubscribe links can all trigger spam filters. Even if your content is strong, problems with email setup or recipient servers can cause deliverability issues.

To improve and protect your deliverability, take a holistic approach, manage your lists carefully, follow technical best practices, and keep your sending patterns and content consistent.

Domain authentication

Your domain is one of your greatest assets. To best leverage it, you should protect it by going through domain authentication.

What is domain authentication and when is it necessary?

Domain authentication refers to the technical standards and protocols that allow for the verification of an email sender's identity. Inbox service providers use authentication to verify that incoming emails are legitimately coming from your brand, therefore protecting your brand and your customers from malicious actors who may spoof your brand. Whether you have sent emails before or are brand new to email marketing, you must authenticate your domain with Yotpo so that we can send emails on your behalf through the platform. Even if you are using another email tool in parallel with Yotpo, you must authenticate each email service provider.

How do I authenticate my domain?

Yotpo’s support articles will guide you throughout the domain authentication process. Check out this detailed article that walks you through the steps of how to authenticate your domain with Yotpo.

Your sender name and from address

Your sender name is the name your subscribers see in their inbox when they receive your emails. Once you authenticate your domain, it’s important to use a sender name that matches your domain. You can set this up in your settings. For example, if your domain is examplestore.com, your sender name should be something like Example Store to match the brand and build trust.

Consistency is key. Once you choose a sender name, especially for a specific type of email, stick with it. For instance, you can use:

Example Store for marketing emails (campaigns, promotions)

Example Store Orders for transactional emails (order and shipping updates)

To learn more about your Email Settings, click here.

Important

Never use a public domain email address (e.g., @gmail.com, @yahoo.com) as your sender address. Using something like my-store@yahoo.com is not complaints and can prevent your emails from reaching your subscribers.

Domain Warm-up

After authenticating your domain and setting up your sender name, it’s vital to follow domain warm-up guidelines to ensure your newly authenticated domain continues to have strong deliverability.

What is domain warm-up and why is it necessary?

Domain warm-up is the process of slowly establishing a reputation for your newly authenticated domain by gradually increasing the volume of emails sent rather than sending to your whole audience at once whether you’ve done email marketing before or not. Domain warming is critical because inbox service providers perceive sudden increases in email volume as very suspicious and indicative of a spammer.

This means starting with Yotpo Email marketing by sending smaller campaigns, starting with your most engaged audience, before building up to audience-wide emails.

Domain Warming will not only protect your brand but will also signal to inbox service providers that you take your emailing practice seriously, and that will positively impact your sender reputation for the rest of your brand’s future!

If you do not complete domain warming after authenticating your domain and begin to send to your whole list at once, it can impact your deliverability negatively, meaning customers might not get your emails. If you have any questions about warming, reach out to our 24/7 support.

Once you have finished warming your domain, follow our Best Practices of Deliverability below to ensure you are consistently sending emails in a way that protects your sending reputation.

Learn more about the warming process

Your email deliverability is important, and it’s in your hands, but we are here to help you along the way with our deliverability best practices.

Understanding Sender Reputation

Sender reputation plays a major role in whether your emails reach your customers’ inboxes or get filtered as spam. Your sender reputation is built over time and depends on how you manage your email sending practices. Think of your sender reputation like a credit score, it improves when your brand sends engaging emails to consented subscribers, and it declines if your emails generate too much negative feedback, such as spam complaints.

What Is Sender Reputation?

Sender reputation is how inbox providers (like Gmail, Yahoo, or Microsoft) assess the trustworthiness of your emails. It applies to both your IP address and your domain:

• Domain Reputation is based on your domain's sending behavior over time. Domain reputation is the most important factor when it comes to your deliverability. It’s more important than IP reputation and sticks with your brand as long as the domain is in use. Subdomains can carry their own reputation, but may inherit part of the root domain’s reputation.

• IP Reputation refers to the sending IP address’s history. Although still relevant, it has less impact today.

What Affects Your Reputation?

There’s no single, universal sender score. Every inbox provider calculates reputation differently, but they look at many of the same signals to get a full picture of your brand’s sending:

• Spam Complaints: Even a small number of complaints can harm your reputation.

• Bounces: High bounce rates, especially hard bounces, are a red flag to providers.

• Unsubscribes: Excessive unsubscribes indicate to inbox providers that your content may not be relevant or wanted.

• List Quality: Sending to unengaged or contacts or those who have not given consent hurts your credibility.

• Sending Patterns: Sudden changes in sending volume or frequency can lead to slow delivery or message deferrals.

• Blocklistings: Using questionable lists or poor practices can get your domain listed on blocklists, affecting all emails sent from that domain.

How to Protect and Improve Your Reputation

• Send only to contacts who have clearly opted in.

• Monitor and maintain clean, engaged email lists.

• Keep a consistent sending schedule.

• Avoid sharp increases in email volume.

Maintaining a strong sender reputation takes time, but it’s one of the most effective ways to ensure your emails land in inboxes, not spam folders.

List Quality, Consent, and Sourcing

Strong email deliverability starts with high-quality contact lists built on clear, explicit consent. You should only send marketing emails to people who have actively opted in to receive them, ideally through a process that reflects their preferences and expectations. Consent isn’t just a best practice; it’s the foundation of a healthy, high-performing email program.

It's critical to ensure that every contact you send to has given consent and is expecting your emails. Sending campaigns to unengaged or non-consenting recipients leads to high unsubscribe and complaint rates, which harms your sender reputation and reduces deliverability. Keep your marketing subscribers separate from other contact types, like customers who haven’t opted into emails, to avoid accidental over-sending.

Email lists naturally decay by about 5–25% per year, so you should regularly clean your lists to remove inactive or invalid email addresses. If you’re importing an existing list, it’s essential to clean it beforehand to avoid sending to outdated or incorrect addresses that can lead to high bounce rates and negatively impact your deliverability from the start.

One of the biggest risks to deliverability is the use of spam traps, email addresses used by inbox providers and blocklist operators to catch senders who don’t follow list hygiene best practices. These traps often appear on purchased, scraped, or low-quality third-party lists. Hitting a spam trap can lead to severe blocklisting and long-term damage to your domain’s reputation.

Purchased, rented, or scraped lists should never be used. These lists pose serious compliance risks, often contain spam traps, and result in excessive complaints and bounces. Sending to these types of contacts can damage your reputation, cause your domain to be blocklisted, and make it nearly impossible to deliver future emails successfully.

To protect your deliverability and maintain a strong sender reputation, always focus on building a clean, permission-based list made up of people who truly want to hear from your brand.

Monitoring Deliverability

Yotpo SMS & Email has the Email Deliverability Dashboard that centralizes your deliverability data, including open rate, click rate, unsubscribe rate, and more. You can learn more about our Email Deliverability Analytics Dashboard article.

To truly understand how your emails are performing, the most reliable source is your brand’s actual sending data from your email service provider (ESP). This data provides direct insight into how your messages are being received, opened, and acted on by your audience.

Key metrics to monitor include open rates, click-through rates, bounce rates, spam complaints, unsubscribe rates, and more.

• Open rates show how many recipients opened your emails. This metric isn’t fully accurate due to privacy protections like Apple Mail Privacy Protection (MPP) and image-blocking settings but can be helpful to monitor directional inbox placement. Very low open rates can be a sign that your emails are landing in the spam folder.

• Click-through rates measure the number of unique clicks from delivered emails, offering a clearer indicator of engagement. However, security software can sometimes generate bot clicks, skewing the results.

• Bounce rates, both soft and hard, should be kept as low as possible. A high bounce rate can indicate issues with list hygiene, authentication, or domain reputation.

• Spam complaint rates show how often subscribers mark your emails as spam, though not all inbox providers report every complaint, so the actual number may be higher than what you see. Spam complaints are to be taken seriously as it's a very negative signal from subscribers. When you receive spam complaints you should evaluate your email content, segmentation and sending frequency to understand why subscribers feel your brand is spam.

• Unsubscribe rates reflect how many recipients choose to stop receiving your emails and can indicate a need to review your content or targeting.

• Inbox placement rate is often misunderstood, it’s not something ESPs can track because they don’t have visibility into where an email lands after it's accepted by the mailbox provider. While some third-party tools estimate inbox placement using seed lists or panel data, these estimates aren’t a reliable substitute for analyzing your brand’s actual engagement and delivery metrics.

Other important indicators include abuse complaints, rare but serious flags that suggest your emails were perceived as unsolicited or harmful. If your brand is generating abuse complaints, you will receive a notice from the Yotpo Messaging Compliance Team. Monitoring these metrics consistently allows you to spot sudden drops in performance and resolve issues before they escalate.

While there are many deliverability testing tools available, both free and paid, they are not substitutes for your actual sending data. Finally, Google Postmaster Tools can be a helpful external resource for checking how well your sending practices align with Gmail’s requirements.

Content Best Practices

Personalization Drives Engagement

Creating high-quality, personalized content is essential for driving engagement and improving email deliverability. Emails that are thoughtfully tailored to your audience’s interests, through personalization and segmentation, are more likely to be opened, clicked, and acted upon. The more relevant your messages are to each recipient, the stronger your engagement and conversion rates will be. Bulk messages should never feel generic; even at scale, personalization signals to both users and inbox providers that your emails are valuable.

Avoid Misleading or Spammy Language

Mailbox providers use advanced spam filters to evaluate incoming emails, factoring in elements like subject lines, images, links, and text balance. While spam trigger words are no longer the primary method for flagging messages, using overly promotional or misleading language can still prompt users to mark your messages as spam, which hurts your reputation. It's best to avoid subject lines written in all caps, overloaded with punctuation, or using exaggerated phrases.

Balance Text and Images

The structure of your email also matters. Emails that are image-only or heavily image-based often get flagged by spam filters. To avoid this, maintain a healthy balance between images and text. A good rule of thumb is to include at least 500 characters of text per email and always add ALT text to your images. This improves accessibility and ensures your message is still readable if images fail to load.

Use Links Sparingly

Limit the number of hyperlinked URLs within your email. Spammers often overload emails with links, both hidden and visible, which can trigger filters. Only include links that are essential and avoid excessive linking, particularly to external websites.

Keep Your Code Clean

Clean and efficient code matters, too. Templates filled with unnecessary or outdated HTML/CSS can raise red flags for spam filters. Simplifying your code can improve your chances of landing in the inbox.

Consider Plain Text Emails

In some cases, sending plain text emails (without heavy formatting) can also help boost deliverability, especially for transactional or win-back messages.

By following these best practices, you help ensure your content is both engaging to recipients and acceptable to inbox providers, leading to stronger inbox placement and campaign results.

Using Flows to Help with Deliverability

Flows play a key role in maintaining good deliverability, especially for brands with irregular sending habits. If you're not sending emails consistently throughout the year, setting up ongoing email flows ensures a steady stream of activity that helps build and maintain a reliable sender reputation with inbox providers.

One of the most effective flows for improving deliverability is the Sunset Flow. This flow is designed to gradually phase out subscribers who have stopped engaging with your emails. The Sunset Flow offers a final opportunity to win back these contacts with targeted messaging before deciding to suppress or delete them from your list. This helps keep your contact list clean and active, which reduces the risk of high bounce rates, spam complaints, and low engagement, common signals that damage your sender reputation.

To learn more about our many different flows including Welcome flows and Win-back flows, click here.

In addition to ongoing flows, you can also run customer win-back campaigns specifically targeted at inactive users. These one-time campaigns help identify which contacts are still interested before you remove them from future sends.

Using structured flows like sunset and customer win-back campaigns ensures you're consistently sending to an engaged audience, which is essential for long-term email performance and deliverability.