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Mailchimp Deliverability: Why it's low & not working?

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    Ever wonder why certain of your well-written emails wind up in the spam bin or, worse, never get delivered at all? Any marketing plan must be email deliverable since it determines how well your message gets into the mailbox of your target audience.

    Now enter Mailchimp, one of the industry titans in email marketing, which guarantees to improve your outreach and streamline your email campaigns. Low deliverability rates can be a problem for users even with its popularity and can impede marketing efforts. Maximizing the effect of your email campaigns requires an awareness of these deliverability problems. We will examine the intricacies of email deliverability with Mailchimp, the reasons for potential issues, and how to raise your email success rate in this article.

    About Mailchimp

    Mailchimp deliverability

    In 2001, Mailchimp was just a side project trying to offer small businesses email marketing services. Ben Chestnut and Dan Kurzius launched it because they recognized a need to develop an affordable, user-friendly email marketing solution specifically designed for small businesses—a market that the bigger, more complicated software companies sometimes ignore.

    Mailchimp has developed over time from a basic email marketing tool into a powerful all-in-one marketing platform. These days, it provides a range of services meant to assist companies in managing more than just emails. These services comprise landing pages, analytics, ad campaigns, social media management, automation, and CRM solutions. With this expansion, small and medium-sized companies should be able to handle and expand their clientele from a single platform.

    Currently having millions of users and sending billions of emails a month, Mailchimp is one of the top email marketing systems in existence. Mostly serving small and medium-sized businesses, it is strong enough to meet the intricate requirements of bigger companies as well. The company has cemented its reputation as a go-to source in digital marketing by its capacity to develop and adjust to shifting market conditions while keeping a sharp emphasis on user experience and simplicity.

    What is email deliverability rate?

    Defined as the proportion of emails that make it into the recipient’s inbox, the email deliverability rate is an important email marketing metric. This rate immediately affects the possible reach and effect of your marketing communications, hence it is crucial for evaluating the success of email campaigns.

    High deliverability rates guarantee that email service providers won’t stop or filter your emails into spam folders, which could otherwise drastically reduce audience interaction.

    Metrics used to measure email deliverability

    Marketers examine many important indicators to gauge email delivery. These include the acceptance rate, which counts the proportion of emails accepted by the server whether they end up in the inbox or the spam folder; the bounce rate, which monitors the proportion of emails that could not be delivered to the recipient’s email address; and the email marked as spam rate, which shows how frequently your emails are reported as unwanted. Because these measurements taken together offer a thorough picture of how well your emails are reaching potential clients, the deliverability rate is an essential element of efficient email marketing plans.

    Common Mailchimp's issues affecting deliverability

    Mailchimp deliverability

    Deliverability of emails can be a complicated issue since many things might influence how well your emails get to the right inboxes. Deliverability percentages with Mailchimp can be adversely impacted by a number of typical problems:

    Poor List Management

    Email addresses on lists that are out-of-date or inaccurate, or that were obtained without the right authorization, may result in significant bounce rates and spam complaints. Emails should only be delivered to interested and legitimate recipients, according to Mailchimp, who highly recommends routine list cleaning and segmentation.

    Inadequate Sender Reputation

    Because Mailchimp users use the same email sending IPs, the activities of one user can have an impact on the reputation of others. Sender reputation for other users sharing that IP may suffer if a Mailchimp user distributes spam or their campaign generates a lot of complaints. Good sender reputations need following email marketing best practices, such as appropriate authentication and regular sending volumes.

    Lack of Authentication

    Email authentication done correctly is essential. Mails without SPF (Sender Policy Framework) or DKIM (DomainKeys Identified Mail) records are more prone to be rejected by ISPs or reported as spam. Mailchimp gives users the ability to configure these authentication methods; it is up to them to do it correctly.

    Content Issues

    Deliverability of your emails is mostly dependent on their content. Emails that are sent to spam folders can be because of dubious keywords, too promotional wording, or badly written HTML. 

    Sending Emails Too Frequently or in Large Volumes

    Irritating subscribers and setting off spam filters can increase unsubscribe rates and spam complaints. Deliverability and subscriber engagement depend critically on the frequency and amount of sends being balanced.

    Significant drops in deliverability

    Any email marketing effort may be negatively impacted by abruptly large declines in email deliverability. Fast resolution and correction of the problem depend on an understanding of the possible reasons behind these dips. Such circumstances can arise for the following typical causes and examples:

    👉 ISPs and email service providers set up email addresses known as Spam Traps to catch spammers. They can entice advertisers that employ bad list sourcing techniques and frequently resemble regular email addresses but are not owned by actual people. Sending an email to a spam trap tells Internet service providers (ISPs) that you don’t maintain good list cleanliness, which may seriously reduce deliverability. A store might, for instance, see a drop in deliverability if they buy an email list that inadvertently contains many spam traps.

    👉 Blacklisting. This happens when email providers add your transmitting IP or domain to a blacklist in order to weed out possible spam. Your emails may be completely blocked or directed to spam folders for all subscribers of that service if you are blacklisted. This can occur if you send too many emails too often or if your emails produce a lot of complaints. One noteworthy instance is the time a well-known marketing company was placed on the Spamhaus blacklist following a campaign that went against sending frequency restrictions.

    👉 High Bounce Rates. Another indicator of deliverability problems can be an abrupt rise in email bounces. Should your email list have a large number of out-of-date or invalid addresses, high bounce rates could result. Emailing these addresses repeatedly tells ISPs that you don’t maintain your list. When an e-commerce company neglected to maintain its membership list for more than a year, for example, deliverability rates fell precipitously.

    👉 ISP Algorithm Changes. Email service providers upgrade their spam detection algorithms on a daily basis. Even little variations in these algorithms can occasionally mark your emails as spam even if they were before allowed. Maintaining current knowledge of email marketing techniques and modifying your tactics as necessary are crucial.

    👉 Subscriber Complaints. Your emails may become less deliverable if more people than usual flag them as junk mail. When the content does not meet the expectations of the subscribers or when permission to communicate is unclear, this frequently occurs.

    Through knowledge of these elements and observation of your email campaigns for these indicators, you can prevent unexpected declines in deliverability. Key tactics to guarantee consistent deliverability rates are to carry out routine audits, keep email lists clean and active, and follow best practices.

    Reliability of Mailchimp's numbers

    Mailchimp monitor

    Although Mailchimp offers a number of indicators to assist companies monitor the performance of their email campaigns, there are situations when one may doubt the veracity and accuracy of these figures. Making better judgments can be facilitated by marketers knowing the restrictions and possible inconsistencies in Mailchimp’s information.

    Deliverability Rate Accuracy

    Deliverability rates are determined by Mailchimp using emails that get through and aren’t rejected by the recipient’s email server. The email may nonetheless wind up in the spam folder, thus this does not ensure that it has arrived in the recipient’s inbox. This means that although Mailchimp claims a high deliverability rate, the crucial indicator for guaranteeing that your message gets viewed by your audience—the inbox placement rate—doesn’t necessarily match it.

    Impact of Open Rate Measurement

    Open rates are traditionally tracked using a tiny pixel embedded in the email. When the email is opened, and the pixel is loaded, it sends a signal back that the email was viewed. However, this method faces several challenges:

    • Privacy Updates. With increasing privacy concerns and updates like Apple’s Mail Privacy Protection, which preloads tracking pixels irrespective of whether the user opens the email, the accuracy of open rate data has diminished. Users who have this feature enabled will always trigger an open, skewing the true engagement metrics.
    • Email Clients Blocking Pixels. Some email clients and security software block images by default, which prevents the tracking pixel from loading even if the email is opened. This leads to underreporting of open rates.

    Reliability of Other Metrics

    Because click and conversion rates are intentional actions by the recipient (such as clicking on a link), they are often more trustworthy than open rates. These metrics can still be impacted, though, by the user’s email settings, Mailchimp’s tracking of interactions, and whether the email is properly shown.

    Technical checks for email deliverability

    To ensure high email deliverability, it’s crucial to implement key technical configurations that validate your emails’ legitimacy and improve your reputation with Internet Service Providers (ISPs):

    1. SPF (Sender Policy Framework). Set up an SPF record to specify which mail servers are authorized to send emails on behalf of your domain, helping to prevent email spoofing.

    2. DKIM (DomainKeys Identified Mail). Implement DKIM to add a digital signature to your emails, ensuring their content remains unaltered in transit and verifying their authenticity.

    3. DMARC (Domain-based Message Authentication, Reporting, and Conformance). Utilize DMARC to define how receivers should handle emails that fail SPF or DKIM checks, and to receive reports on email delivery status, enhancing your control over email security.

    4. List Hygiene. Regularly cleanse your email list by removing inactive subscribers and invalid addresses to maintain a healthy sender reputation and reduce bounce rates.

    5. Proper Email Formatting. Ensure emails are correctly formatted with clean HTML and responsive designs to avoid being flagged as spam.

    6. Blacklist Monitoring. Regularly check if your sending IP or domain is on any blacklists and take action to resolve any listings to maintain uninterrupted email delivery.

    Improving email deliverability with Warmy.io


    One specialist solution created to improve email deliverability—a crucial component of every email marketing campaign—is Warmy.io. Warmy.io offers a full range of tools to guarantee your emails not only reach the inbox but also successfully engage your audience by concentrating on important aspects of email security and performance.

    Features of Warmy.io

    Email Warm-up

    Automatically warms up your email accounts to increase the sender’s reputation and ensure high deliverability.

    Free SPF and DMARC Record Generator

    SPF generator

    Provides easy tools to create SPF and DMARC records, crucial for authenticating your email and protecting against spoofing.

    Warmy.io’s deliverability tests provide actionable insights, allowing you to make necessary adjustments before your campaign goes live. This preemptive approach helps in mitigating issues that could lead to high bounce rates or spam complaints. Additionally, the email template checker ensures your content is optimized for engagement and not likely to trigger spam filters.

    email template checker

    Tests your email templates against common spam filters and suggests improvements to increase open rates.

    Benefits of Using Warmy.io

    Using Warmy.io can significantly boost your email deliverability rates. By warming up your email accounts, Warmy.io helps in gradually building your sender reputation with ISPs. This process involves sending and interacting with emails in a way that mimics natural behavior, thus avoiding red flags commonly associated with spam. Moreover, the SPF and DMARC record generators ensure your emails are authenticated, reducing the likelihood of being rejected by email servers.

    To help businesses realize the benefits of optimized email deliverability, Warmy.io offers a 7-day free trial that allows users to test all features without any commitments.


    Your email marketing initiatives will work as well as possible if you optimise email deliverability. Even though Mailchimp provides a powerful platform with a ton of capabilities, making sure your messages get to your audience’s inboxes requires a grasp of and ability to resolve deliverability problems. Essential stages in this process are putting best practices like list hygiene, email authentication setup, and routinely verifying for blacklist inclusion into effect.

    Additionally, you may get a lot of help improving your email deliverability with services like Warmy.io. Warmy.io enhances the capabilities of Mailchimp with tools meant to enhance sender reputation and guarantee email standard compliance, therefore securing the route of your emails to the inbox.

    📜 Related article:


    1. What is Mailchimp deliverability?

    Deliverability of emails sent with Mailchimp is the capacity of such emails to reach the inboxes of recipients without being rejected as spam or blocked by email servers.

    2. Why is my Mailchimp deliverability low?

    Among the many reasons why Mailchimp deliverability is low include bad list management, a weak sender reputation, improper email authentication (SPF, DKIM, DMARC), and content that triggers spam filters.

    3. How can I improve my Mailchimp deliverability?

    To enhance Mailchimp deliverability, ensure that your email lists are clean and updated, implement SPF, DKIM, and DMARC records for email authentication, avoid spammy content, and maintain consistent sending volumes

    4. Can using a tool like Warmy.io help with Mailchimp deliverability?

    Indeed, Mailchimp deliverability can be much increased by employing services like Warmy.io. Warmy.io offers services to test and improve email campaigns for improved deliverability, warms up your email accounts, and guarantees that your emails are authenticated.

    5. How often should I clean my Mailchimp email list?

    To increase deliverability and engagement rates, clean your Mailchimp email list at least once every six months to eliminate invalid email addresses and inactive subscribers.

    6. What is the best way to monitor Mailchimp deliverability performance?

    Frequent review of your campaign reports for open, click, bounce, and spam complaints is an efficient way to monitor Mailchimp deliverability performance. Using outside resources like Warmy.io can also yield more in-depth analysis and diagnosis.

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