Will exceeding email size limits and causing clipping affect overall email deliverability and sender reputation?
Michael Ko
Co-founder & CEO, Suped
Published 11 Jul 2025
Updated 18 Aug 2025
8 min read
For many years, the general consensus was that exceeding email size limits, particularly the 102KB threshold that leads to Gmail clipping, was primarily a display issue. The common thought was that if your email was clipped, it just meant recipients had to click a 'View Entire Message' link to see all the content. While inconvenient, it wasn't widely believed to directly impact whether your email reached the inbox or influenced your sender reputation. I’ve heard this sentiment echoed countless times in discussions.
However, the landscape of email deliverability is constantly evolving. As mailbox providers become more sophisticated in evaluating sender behavior and user engagement, even seemingly minor issues like email clipping can contribute to broader deliverability challenges. My perspective, based on observing various sending patterns and their outcomes, is that while it may not be an immediate hard block, consistent clipping can indeed have a subtle, cumulative effect on your overall email deliverability and sender reputation over time.
Understanding email clipping
Email clipping happens when the HTML code of your email exceeds a certain size limit set by email clients. For instance, Gmail clips messages larger than 102KB, hiding the overflow behind a 'View Entire Message' link. While this isn't a direct penalty, it disrupts the recipient's experience. Imagine your carefully crafted call-to-action or critical information being hidden behind a click, or a footer with an unsubscribe link being out of immediate sight.
This leads to potential issues with engagement. If recipients don't click to view the full message, your open rates and click-through rates might be artificially suppressed. Mailbox providers interpret low engagement as a sign that your content isn't relevant or desirable. This can subtly degrade your sender reputation over time, even if individual emails aren't bouncing.
The impact isn't always immediate or obvious. It's more like a slow erosion of trust. When your emails consistently get clipped, it sends a signal to ISPs that your messages might be less user-friendly or optimized. This can influence their filtering decisions, making your future emails more prone to landing in the spam folder rather than the inbox, even those that fall within the size limits.
The subtle impact on sender reputation
One of the most concerning indirect impacts of email clipping is its potential effect on sender reputation. If your unsubscribe link or preference center is hidden due to clipping, recipients may become frustrated. Rather than digging through a clipped email to find an unsubscribe option, they might resort to the easier path: marking your email as spam. This directly harms your sender reputation. A high spam complaint rate is one of the quickest ways to damage deliverability.
Additionally, large email sizes can lead to slower load times, especially on mobile devices or slower connections. A slow-loading email provides a poor user experience, increasing the likelihood that a recipient will abandon the email before fully engaging with it. This lack of engagement, when consistent, can signal to mailbox providers that your emails are not valuable to their users, leading to poorer deliverability. This is supported by insights that longer and heavier emails can have negative consequences for deliverability.
While an email clipping once or twice might not immediately land you on a blocklist (or blacklist), a pattern of sending oversized emails can gradually erode your sender reputation. Mailbox providers, including Yahoo and Outlook, prioritize the user experience. If your emails consistently provide a suboptimal experience due to clipping, it can negatively impact your sender score and lead to increased spam folder placement for all your sends, even those that are perfectly sized.
Email attachments and overall size
Beyond HTML clipping, the overall size of your email, especially due to large attachments, can significantly affect deliverability. While attachments are sometimes necessary, they add considerable weight to your emails. This added weight can lead to emails being flagged by spam filters or even bounced entirely if they exceed the recipient's mailbox limits. PDF attachments are a common culprit for increasing email size.
Repeated bounces from oversized emails, particularly if they are hard bounces (indicating a permanent delivery failure), can severely damage your sender reputation. Mailbox providers see these as signs of poor list hygiene or irresponsible sending practices. Even soft bounces (temporary delivery issues) can, if frequent, negatively impact how ISPs perceive your sending domain. HTML email size and attachments are key factors.
The critical point is that any factor that contributes to a negative user experience or signals irresponsible sending, whether it's clipping or large attachments, adds to the cumulative data points ISPs use to assess your sender reputation. If you're consistently sending large emails, even if not every one is clipped, the overall pattern can still count against you.
Best practices for email size and deliverability
To ensure optimal deliverability and maintain a strong sender reputation, it is crucial to manage your email size proactively. Keeping your emails lean not only helps avoid clipping but also improves loading times and overall recipient satisfaction. This commitment to a better user experience is exactly what mailbox providers look for.
Here are some strategies to prevent clipping and improve your email deliverability:
Optimize HTML code: Minify HTML and CSS by removing unnecessary comments, whitespace, and redundant code. Some email service providers (ESPs) do this automatically.
Compress images: Ensure images are optimized for web without sacrificing quality. Use appropriate formats like JPG for photos and PNG for graphics with transparency.
Limit content: Keep your email content concise and to the point. Focus on conveying your message efficiently rather than including excessive text or graphics. Long URLs can also add to size, so use link shorteners when appropriate.
Avoid unnecessary attachments: If you must include large files, consider hosting them online and linking to them in your email instead of attaching them directly. This also applies to large GIF files.
Clipped email experience
When an email exceeds size limits, email clients like Gmail will clip the message, displaying only a portion and a link to view the rest. This can lead to important content, such as calls to action, images, or even the unsubscribe link, being hidden. Recipients might miss critical information or become frustrated, leading to a negative engagement signal. Outlook for iOS can also clip emails.
Impact on sender reputation
A clipped email can negatively affect your sender reputation in several ways:
Reduced engagement: Lower open and click rates as recipients may not see or interact with the full message.
Increased spam complaints: Frustrated recipients, unable to find the unsubscribe link, might mark emails as spam.
Perceived low quality: ISPs may view consistently clipped emails as a sign of poor email design or user experience.
Optimal email size practices
Keeping your emails under 100KB, particularly the HTML body, is a widely recommended best practice. This ensures that your entire message, including critical calls-to-action and unsubscribe links, is visible without requiring recipients to click extra links. Focus on concise copy and efficient use of images. Remember, extra-large emails can hinder your message's intended glory.
Maintaining deliverability
By adhering to size limits, you enhance the user experience, which in turn leads to better engagement metrics. Higher engagement (opens, clicks, low spam complaints) sends positive signals to mailbox providers. This proactive approach strengthens your sender reputation, making it more likely that your emails consistently land in the inbox. It's a continuous effort that yields long-term benefits for your email program.
Views from the trenches
In the world of email marketing, insights from peers and experts are invaluable. Here's what I've gathered from discussions and observations within the community regarding email size and clipping:
Best practices
Actively optimize email templates to keep their HTML size below 100KB.
Always position critical elements like unsubscribe links and calls-to-action within the visible portion of the email to ensure recipients can easily access them.
Prioritize a clean and engaged email list, as a healthy list can mitigate some of the minor issues caused by occasional clipping.
Regularly monitor your email performance metrics, particularly engagement rates and spam complaints, to detect any potential negative trends early.
Common pitfalls
Mistakenly believing that email clipping is purely a cosmetic issue and has no impact on deliverability or sender reputation.
Failing to place unsubscribe links prominently, leading to frustrated recipients marking emails as spam.
Overlooking the cumulative effect of consistently sending oversized emails, which can slowly degrade sender reputation over time.
Neglecting to compress images and minify HTML/CSS, leading to unnecessarily large email file sizes.
Expert tips
Consider using email design platforms that automatically optimize HTML code to reduce file size and prevent clipping.
Implement A/B tests with different email lengths and designs to understand what resonates best with your audience while staying within size limits.
Focus on the 'above the fold' content, ensuring your core message and primary call to action are immediately visible to all recipients.
Keep an eye on updates from major mailbox providers regarding their preferred email practices and size recommendations.
Expert view
Expert from Email Geeks says that clipped messages might under-report opens if the open tracking pixel is not visible without further action. However, clipping generally does not affect unrelated messages or other senders from the same domain.
December 9, 2024 - Email Geeks
Marketer view
Marketer from Email Geeks says that there could be an increase in spam reports if the unsubscribe link is hidden or 'below the fold' due to clipping, as it's often easier for recipients to mark an email as spam than to find the unsubscribe option.
December 9, 2024 - Email Geeks
Maintaining optimal email size for deliverability
While email clipping might not trigger an immediate, severe penalty like a direct blocklisting (or blacklisting), its consistent occurrence can indeed affect your overall email deliverability and sender reputation. The impact is often indirect, stemming from a degraded user experience that leads to lower engagement metrics and potentially higher spam complaints. Mailbox providers value positive recipient interaction, and anything that detracts from that can subtly harm your standing.
Therefore, I recommend viewing email size limits not just as technical constraints, but as opportunities to optimize your email content for maximum impact and deliverability. Prioritizing concise design and efficient coding ensures that your message is fully received, appreciated, and acted upon, safeguarding your sender reputation in the long run. Adopting these best practices will help you avoid the potential pitfalls of oversized emails.
Gmail clips messages larger than 102KB, hiding the overflow behind a 'View Entire Message' link. While this isn't a direct penalty, it disrupts the recipient's experience. Imagine your carefully crafted call-to-action or critical information being hidden behind a click, or a footer with an unsubscribe link being out of immediate sight.
Yahoo and 
Outlook, prioritize the user experience. If your emails consistently provide a suboptimal experience due to clipping, it can negatively impact your sender score and lead to increased spam folder placement for all your sends, even those that are perfectly sized.
