Is MailChimp a good choice for newsletter deliverability with a growing subscriber list?
Michael Ko
Co-founder & CEO, Suped
Published 25 Apr 2025
Updated 19 Aug 2025
7 min read
When you are managing a growing newsletter, questions about your email service provider (ESP) and its impact on deliverability are natural. Mailchimp has long been a popular choice, particularly for small businesses and those just starting out in email marketing. Its user-friendly interface and extensive feature set make it appealing, but as subscriber lists expand, questions about its suitability for maintaining high deliverability rates often arise.
I've seen many marketers wonder if a platform primarily associated with smaller-scale operations can genuinely support the deliverability needs of a newsletter scaling to tens of thousands of subscribers monthly, with steady weekly growth. The good news is that for many growing newsletters, Mailchimp can indeed be a viable option, provided certain best practices are followed. The key lies in understanding how Mailchimp handles deliverability and what limitations might emerge with significant volume.
Mailchimp's deliverability foundation
Mailchimp has a strong infrastructure that supports its users' deliverability. They invest in the necessary tools to meet industry standards, which is crucial for any ESP, especially one serving a large and diverse customer base. This means that for basic deliverability, Mailchimp typically performs well, as long as sender practices are sound.
For a newsletter sending around 40,000 emails per month and growing, Mailchimp's shared IP pools are generally sufficient. This volume is not considered excessively large in the broader context of email marketing, and shared IPs can actually be beneficial, as the reputation is aggregated across many senders. However, it also means that your sending practices contribute to, and are affected by, the collective reputation of the pool. Mailchimp is known to police their customers fairly well, which helps maintain the overall quality of their shared IPs.
However, relying solely on an ESP's reputation isn't enough. Your own sending habits play a significant role. Maintaining a clean list, avoiding spam traps, and adhering to engagement best practices are paramount, regardless of your ESP. If you're seeing emails going to spam, it often points back to your practices rather than the ESP itself.
Authentication and DMARC
One area where Mailchimp, like many other ESPs, has a particular approach is with email authentication. Specifically, the Sender Policy Framework (SPF) alignment. Mailchimp typically uses its own domain in the RFC5321.From (Mail From) address for SPF validation, which means your domain won't align for SPF. This can be a point of concern for senders aiming for strict DMARC enforcement.
The Mailchimp approach to SPF
Mail From domain: Mailchimp uses its own domain (e.g., mcsv.net) for the Mail From (RFC5321.From) address. This is the domain checked by SPF.
SPF pass: SPF will pass because mcsv.net is authorized to send mail from Mailchimp's IPs.
SPF alignment: Your From header domain (what your recipients see) will not align with mcsv.net. This means SPF will fail DMARC alignment.
While SPF alignment might not occur, Mailchimp reliably ensures DKIM (DomainKeys Identified Mail) alignment. DMARC (Domain-based Message Authentication, Reporting, and Conformance) only requires either SPF or DKIM to pass and align for a message to be considered authenticated. So, as long as DKIM aligns, your emails should pass DMARC successfully. For most newsletters, relying on DKIM alignment for DMARC is perfectly robust. If you are ever in doubt, you can use a free email deliverability tester to check your authentication setup.
Scalability and feature considerations
One common concern with ESPs when a list grows rapidly is the sending speed. While Mailchimp is generally reliable, some users with very large lists (e.g., over a million subscribers) have noted that sending can take a few hours to complete. This sending throttle is typical for shared IP environments, as ESPs manage their sending reputation by pacing email delivery. For a newsletter sending 40,000 emails per month, this speed limitation is unlikely to be a significant issue, as the volume is relatively small in the grand scheme of email sending.
Pros for growing newsletters
Ease of use: Mailchimp's intuitive interface makes it easy to create and send newsletters, even for beginners. This saves time and reduces technical hurdles.
Reliable deliverability:Mailchimp generally handles the technical aspects of getting your emails to the inbox, including managing IP reputation and handling bounces, as noted in various reviews.
Feature set: It offers a good range of features, including segmentation, A/B testing, and basic automation, which are useful as your list grows.
Cons for growing newsletters
Pricing: As your subscriber list grows, Mailchimp's pricing can become relatively expensive compared to other platforms, especially if you have duplicate or unengaged contacts.
Advanced automation: While it has basic automation, highly complex or multi-channel automation flows might be limited compared to more specialized platforms.
SPF alignment: The inability to control the RFC5321.From domain means SPF will not align, requiring reliance on DKIM for DMARC enforcement.
The suitability of Mailchimp for a growing newsletter also depends on your specific needs beyond core deliverability. If your primary goal is to send newsletters with good inbox placement and leverage standard marketing features, Mailchimp is likely to serve you well. However, if you anticipate needing highly complex segmentation, deep integrations with other systems, or extensive custom automation, you might eventually explore other platforms better suited for those advanced requirements. For most newsletters, however, the existing feature set and general robustness will suffice.
Best practices for senders
Even with a robust ESP, your own practices are critical for maintaining good deliverability. I always emphasize that sender reputation is built on consistent, positive engagement. This means actively managing your subscriber list.
Regular list cleaning is non-negotiable. Removing inactive subscribers and invalid email addresses prevents bounces and reduces the risk of hitting spam traps, which can severely damage your sender reputation and lead to blacklisting (or blocklisting). Additionally, ensure your signup processes are transparent and subscribers explicitly opt-in.
Another crucial aspect is monitoring. Even if Mailchimp handles much of the backend, you should still keep an eye on your deliverability metrics. Pay attention to open rates, click-through rates, bounce rates, and spam complaint rates. These indicators can alert you to potential issues early on. Tools like Google Postmaster Tools can offer insights into your domain's reputation with Google. Regularly checking if your domain or IP is on any email blocklist or blacklist is also a good practice.
Navigating DMARC with Mailchimp
If you're considering enforcing a DMARC policy with Mailchimp, it is crucial to start with a p=none policy and monitor your DMARC reports closely. This allows you to identify any legitimate email streams that might be failing authentication before moving to a quarantine or reject policy. This monitoring process is what truly builds confidence.
While Mailchimp's inability to provide SPF alignment for your domain might seem like a drawback for strict DMARC enforcement, DKIM's robustness usually makes this a non-issue. DKIM signatures are generally stable and less prone to breaking than SPF, especially across forwarding paths. It is important to remember that DMARC only needs one of SPF or DKIM to align and pass. As Mailchimp reliably provides DKIM alignment, you can proceed with DMARC implementation with confidence.
For specific issues, like high abuse complaints from particular providers, even with Mailchimp, the solution often involves improving list quality and engagement. Mailchimp provides tools and analytics to help you monitor campaign performance and audience behavior, which are essential for diagnosing and resolving deliverability challenges.
Summary
For a newsletter with 40,000 subscribers and steady growth, Mailchimp remains a good choice for deliverability. Its robust infrastructure, combined with its diligent customer policing, ensures that the shared IP reputation is generally well-maintained. While it may not offer every advanced feature or SPF alignment for DMARC, its core deliverability is solid, and its DKIM alignment is reliable.
The key to sustained success with Mailchimp, or any ESP, lies in your active management of email marketing best practices. This includes rigorous list hygiene, encouraging engagement, and closely monitoring your campaign metrics and authentication reports. By doing so, you can ensure your newsletter continues to reach the inbox effectively as your subscriber base expands.
Views from the trenches
Best practices
Actively clean your email list by removing unengaged subscribers and invalid addresses regularly. This improves sender reputation and reduces bounce rates.
Always use double opt-in for new subscribers to ensure high quality and genuine interest, minimizing spam complaints.
Monitor your email engagement metrics, such as open rates and click-through rates, to understand subscriber interest and adjust content as needed.
Common pitfalls
Not managing list growth proactively can lead to higher bounce rates and spam complaints, especially with acquired or old lists.
Ignoring DMARC reports, which can hide authentication failures that might impact deliverability, even with reliable DKIM.
Failing to segment your audience, which can result in sending irrelevant content and lower engagement.
Expert tips
Leverage Mailchimp's segmentation features to tailor content to different subscriber groups, which can boost engagement and deliverability.
While Mailchimp's SPF alignment might not be ideal for some DMARC configurations, its DKIM is typically strong enough to ensure DMARC passes.
Consider the long-term cost as your list grows; Mailchimp's pricing structure can become less competitive at higher subscriber counts.
Marketer view
Marketer from Email Geeks says they managed an email list of over 1 million active subscribers and sent newsletters twice a week with Mailchimp, finding it suitable for basic deliverability, though large sends could take hours.
2021-09-23 - Email Geeks
Marketer view
Marketer from Email Geeks says that Mailchimp's deliverability should be fine as long as proper address acquisition methods are used, noting that Mailchimp effectively manages its customer base.
Mailchimp reliably ensures DKIM (DomainKeys Identified Mail) alignment. DMARC (Domain-based Message Authentication, Reporting, and Conformance) only requires either SPF or DKIM to pass and align for a message to be considered authenticated. So, as long as DKIM aligns, your emails should pass DMARC successfully. For most newsletters, relying on DKIM alignment for DMARC is perfectly robust. If you are ever in doubt, you can use a free email deliverability tester to check your authentication setup.
Mailchimp generally handles the technical aspects of getting your emails to the inbox, including managing IP reputation and handling bounces, as noted in various reviews.
