Email Deliverability Issues? Top Causes and Fixes
Have your email open rates tanked recently? Noticing a significant drop in your overall email marketing performance, and puzzled about what happened or what to do to improve the situation?
It’s possible you’ve stumbled into an email deliverability pitfall. There are scary terms here like “spam traps” and “blacklists,” but don’t worry — it’s a recoverable situation.
As an email marketing agency, our success requires a strong understanding of email deliverability. If emails aren’t reaching inboxes, no one is getting results. If you need support, explore our Email Deliverability Consultation Service. We can help you recover your email marketing performance, quickly.
Here’s what you need to know about the most common causes of email deliverability issues and how to fix them.
Email Deliverability 101
Before we explore how to solve deliverability issues, let’s break down some key terms you’ll need to understand to wrap your head around the problem.
Email Deliverability
Email deliverability refers to the ability of your emails to reach the inbox of your recipients without being blocked by spam filters or landing in the junk folder. Deliverability is influenced by various factors, which we’ll explore below. Depending on your email system, it’s measured as a score or percentage, where say 99.7% deliverability means 99.7% of your emails are making it through to inboxes (which is good).
Email Service Providers (ESPs)
Email Service Providers are companies or platforms that offer email services to users, including the ability to send, receive, and store emails. Examples of personal ESPs include Gmail, Yahoo Mail, and Outlook.com. In addition, there are ESPs focused on marketing and bulk email campaigns, such as Klaviyo, SendGrid, and Hubspot. These marketing ESPs provide tools for creating, sending, and tracking email campaigns and newsletters. It’s a little confusing but all ESP providers work hard to filter out as much spam as possible to keep their customers happy. To do so, they each have their own set of spam filters and deliverability rules to recognize junk mail and move it to spam folders.
Inbox Placement
Inbox placement refers to the ability of an email to be delivered directly to the recipient’s inbox, as opposed to being filtered into a spam folder, junk mail, or other secondary folders like promotions or updates. It’s an important metric for email marketers because emails that land in the main inbox are far more likely to be seen, opened, and acted upon by recipients. However, we’ll say right now that landing in the promotions tab isn’t something we consider a “deliverability” issue. When we talk about poor deliverability, we’re really talking about emails going to places where they won’t be seen by customers like either bouncing or landing in spam/junk folders.
Spam Filters
Spam filters are tools used by email service providers to screen incoming emails and separate unwanted or unsolicited emails from those legitimately wanted by the end user. These filters scrutinize various aspects of an email, including its source, content, and the authenticity of the sender (verified through protocols like SPF, DKIM, and DMARC), to determine if it should be delivered to the recipient’s inbox, sent to the spam/junk folder, or blocked entirely. The criteria for spam filtering are constantly evolving and Google and Yahoo introduced new requirements in February 2024 that are causing a surge of deliverability issues for businesses that didn’t prepare for them.
Spam Traps
Spam traps are email addresses used by organizations to identify and catch spam. They can appear as legitimate email addresses but do not belong to real users and are not used for genuine communication. Sending an email to a spam trap address is usually a sign of poor list hygiene or sourcing practices and can severely harm a sender’s reputation with ISPs and email service providers. You can identify and remove spam traps by using a service like Zero Bounce to support list cleaning initiatives.
Blacklists
Blacklists, also known as DNS-based Blackhole Lists (DNSBLs) or Real-time Blackhole Lists (RBLs), are databases compiled by various organizations to list IP addresses or domains known to send spam or malicious content. Email service providers and receiving servers consult these blacklists as part of their spam filtering processes. If an IP address or domain sending emails is found on a blacklist, emails originating from it are more likely to be rejected or filtered directly into the spam/junk folder, significantly impacting email deliverability.
Open Rates
Open rates represent the percentage of sent emails that are opened by recipients. It’s a key metric in email marketing that helps gauge the engagement level of an audience with the email content. High open rates typically indicate relevant, well-targeted content and a healthy email list, while low open rates — especially sudden drops in open rates — may indicate email deliverability issues.
Bounce Rates
Bounce rates refer to the percentage of emails that were not delivered to recipients’ inboxes and returned to the sender. Bounces are classified as either “hard” (permanent issues like invalid email addresses or rejection due to spam filters) or “soft” (temporary problems, such as a full mailbox). A high bounce rate can negatively impact a sender’s reputation and deliverability and needs further investigation.
Spam Complaints
Spam complaints occur when recipients mark an email as spam or junk in their email client. This action not only removes the email from their inbox but also signals to email service providers that the sender might be sending unwanted or unsolicited emails. High levels of spam complaints can lead to deliverability issues and damage the sender’s reputation.
Email Deliverability Issues: Common Causes and Fixes
When you suspect you may have deliverability issues, the first thing to do is check your metrics and try to identify and isolate the issue. This involves checking bounce rates, examining bounce messages, looking at spam complaints, checking your domain authentication protocol, looking at your account settings to see what your sending settings are. Once you’ve done this mini-audit, you will be able to better understand the cause and apply fixes.
Here’s a summary of common root causes and fixes we see as email marketing agency:
Long-Term Strategies to Prevent Email Deliverability Issues
Email deliverability issues are mostly avoidable by having strong best practices in place as part of your email marketing strategy. For example:
List Cleaning
List cleaning, also known as email list hygiene, refers to the process of removing inactive, invalid, or unengaged subscribers from your email list. This practice helps improve email deliverability and engagement rates by ensuring that emails are only sent to recipients who are interested and active, reducing the risk of bounces and spam complaints.
Opt-in Setup
Opt-in setup is the process by which recipients give their explicit permission to receive emails or newsletters from a sender. This can be a single opt-in, where the user subscribes with just one action, or a double opt-in, which requires the user to confirm their subscription through a follow-up email. Opt-in setups are important for making sure you’re building a healthy, engaged email list and complying with email marketing regulations.
Sending Infrastructure
The sending infrastructure refers to the technical setup used to send out bulk emails, including the email servers, IP addresses, and domain names involved in the email delivery process. A robust sending infrastructure can be either shared among multiple senders or dedicated to a single sender (dedicated IPs), affecting deliverability and sender reputation based on the quality and reputation of the infrastructure used.
DNS Records (SPF, DKIM, DMARC)
DNS Records related to email authentication include:
SPF (Sender Policy Framework): A DNS text record that specifies which mail servers are permitted to send email on behalf of your domain, helping to prevent email spoofing.
DKIM (DomainKeys Identified Mail): An email authentication method that allows the receiver to check that an email was indeed sent and authorized by the owner of that domain, enhancing security and deliverability.
DMARC (Domain-based Message Authentication, Reporting, and Conformance): A policy and reporting protocol that builds on SPF and DKIM records, allowing domain owners to define how an email should be handled if it doesn’t pass authentication checks. It also provides reports on actions taken, improving email security and integrity.
Consent Management
Consent management in email marketing involves obtaining and documenting the permission of recipients before sending them emails. It includes managing opt-ins and opt-outs effectively, respecting subscriber preferences, and complying with data protection and privacy regulations such as GDPR (General Data Protection Regulation) and CCPA (California Consumer Privacy Act). Effective consent management ensures that emails are sent to users who have explicitly agreed to receive them, thereby improving engagement and reducing spam complaints.
When To Seek Help
Deliverability issues are complex and we genuinely wish those problems on no one. It’s a hole you have to climb out of. The good news? It is possible. And with some strategic support, you can not only recover your email metrics but also ensure you don’t have deliverability issues again.
Here’s when to reach out to an expert for support:
- You’re having trouble diagnosing the problem.
- You need the problem resolved as quickly as possible.
- You need support with email best practices like list cleaning, opt-in management, or consent management.
- You need alternatives to purchased lists.
- You need the ability to measure and monitor email deliverability to spot issues early on.
About Centric Squared
Centric Squared is a growing email marketing agency driving significant revenue for our clients through Email and SMS Marketing. With a focus on CRM-driven marketing, our team of global marketing experts has generated $3 million in revenue for our clients last year alone. We’re committed to transforming businesses with data-driven strategies that enhance customer engagement and foster resilient growth.
Our Email Deliverability Consulting Services are designed to diagnose, troubleshoot, and resolve these issues, putting your email marketing back on the path to success.
