What is the Google error message when an email exceeds size limits?
Matthew Whittaker
Co-founder & CTO, Suped
Published 6 Jul 2025
Updated 17 Aug 2025
8 min read
Sending emails seems straightforward until you hit an unexpected roadblock, like a bounce-back message stating your email is too large. This is a common issue, especially when dealing with attachments, and can be particularly frustrating when it comes from a major provider like Google.
Understanding why your emails are rejected and what specific error messages mean is crucial for maintaining good email deliverability. When an email exceeds Google's size limits, you'll receive a bounce message that clearly indicates the problem. Knowing these messages helps you quickly diagnose and resolve the issue, ensuring your important communications reach their intended recipients.
Understanding Google's email size limits
Most email providers, including Google, impose limits on the total size of an email. For Gmail, this limit is generally 25 MB for both incoming and outgoing messages. This 25 MB limit applies to the combined size of the email body and all its attachments, after MIME encoding. It is important to note that MIME encoding can increase the size of attachments by about 33%, so a 20 MB file could easily exceed the 25 MB limit once encoded. You can learn more about general attachment and message size limits across various providers.
While Gmail typically handles larger attachments by converting them into Google Drive links for external recipients, this automatic conversion may not always prevent a bounce message, especially if the total email size (including inline images and complex HTML) significantly exceeds the threshold or if there are issues with the conversion process. Additionally, while Google Workspace allows for larger internal messages, external sending still adheres to the standard 25 MB limit.
These limits are in place to prevent server overload, manage storage, and mitigate spam. Large emails can consume significant bandwidth and storage, leading to slower delivery times or even blocking by recipient servers. When you run into these limits, Google will typically send back a specific error message, giving you a clear indication of why the email failed to send.
The exact error message you'll see
When your email exceeds Google's message size limits, the most common bounce-back message you'll encounter includes the error code 552 (or 552 5.3.4). This SMTP error indicates that the requested mail action was aborted due to exceeding storage allocation, which in this case refers to the message size limit. Essentially, Google's servers are telling your sending server that the email is too big to accept.
The full error message will typically look something like this. It is quite specific, directing you to Google's support page for more details, which is helpful for troubleshooting.
Example Google Email Size Limit Error Messageplaintext
552-5.3.4 Your message exceeded Google's message size limits. Please visit
552-5.3.4 https://support.google.com/mail/?p=MaxSizeError to view our size
552 5.3.4 guidelines.
This error isn't usually tied to your sender reputation or IP address being on a blocklist or blacklist. It's a straightforward technical rejection based on message size, similar to a mailbox quota exceeded error. However, frequent sending of oversized emails can still negatively impact your overall deliverability by causing delays and increasing bounce rates. This is why addressing these errors promptly is important.
Understanding 552 errors
The 552SMTP error code specifically means "Requested mail action aborted: exceeded storage allocation." While it often refers to message size, it can also indicate that the recipient's mailbox is full. For Google's size limits, it consistently points to the message being too large.
Common causes of oversized email bounces
Several factors can contribute to an email exceeding Google's size limits, often going beyond just large file attachments. While attachments are the most obvious culprit, the overall message structure can also play a significant role. This includes the size of the HTML content, especially if it contains many inline images or complex formatting, and the length of the email thread.
Even without direct attachments, an email can become too large for several reasons. Long email conversations with extensive reply chains, embedded images (like logos or tracking pixels), and complex HTML signatures can all contribute to the overall message size. Each of these elements adds to the total data that needs to be transmitted and stored, potentially pushing the email over the 25 MB limit once MIME encoded.
It's also important to remember that while Google has its limits, the recipient's email server may have different (and often lower) restrictions. If you're sending to someone using a different provider with a smaller maximum message size, your email could still bounce even if it's within Google's allowed limits. You can check the message and attachment size limits for various email providers to avoid such scenarios.
Strategies for sending large files and avoiding errors
The most effective way to send large files via email without encountering Google's size limits is to use cloud storage services. Gmail itself integrates seamlessly with Google Drive, automatically converting attachments over 25 MB into Drive links. You can also manually upload files to Google Drive, Dropbox, or OneDrive, and then share the link in your email. This bypasses the size limit entirely and often ensures quicker delivery.
If cloud storage isn't an option, consider compressing your files before attaching them. Zipping folders or using file compression software can significantly reduce the file size. For images within your email body, optimize them for web use. Large, high-resolution images can quickly inflate your email size, even if they are inline. Reducing their dimensions and file size without compromising too much quality can help. Read our guide on how email file size affects deliverability.
Break up content: If you have a very long email thread or extensive inline content, consider splitting it into multiple messages or summarizing key points with links to full content hosted externally.
Clean up email signatures: Overly complex HTML signatures with many inline images can add to message size. Simplify them or host images externally.
Test with an email deliverability tool: Before sending to a large list, use an email deliverability tester to check for potential size-related issues or other factors that might affect inbox placement.
By implementing these strategies, you can minimize the chances of your emails bouncing due to size limits. It's not just about avoiding errors, but also about ensuring a smoother and more reliable email experience for both you and your recipients. Remember, effective email management is a key component of overall email deliverability.
Views from the trenches
Best practices
Use cloud storage for attachments exceeding 10MB to ensure reliable delivery.
Optimize all inline images and email template HTML to reduce overall message weight.
Regularly review bounce messages for
552
errors and adjust sending practices accordingly.
Inform recipients in advance if you're sending large files via shared links.
Common pitfalls
Ignoring the "Your message exceeded
Google's
message size limits" error, leading to repeated bounces.
Assuming 25MB is a strict limit without accounting for
MIME
encoding overhead (which can add 33%).
Expert tips
Always use a test account to verify email size and rendering before a large send.
For automated systems, implement logic to switch to cloud links if attachment size exceeds a threshold.
Educate your team on best practices for sending large files to avoid common pitfalls.
Monitor email bounce logs for
552
errors to identify problematic campaigns or senders.
Marketer view
Marketer from Email Geeks says they found it challenging to test
2023-10-27 - Email Geeks
Expert view
Expert from Email Geeks says that
2023-10-27 - Email Geeks
Final thoughts on managing email size
Dealing with Google's email size limits is a common aspect of email management. By understanding the specific error messages, the underlying causes, and the various strategies for sending larger files, you can significantly improve your email deliverability. The key is to be proactive, optimizing your email content and leveraging cloud storage solutions when necessary.
Regularly monitoring your bounce rates and understanding the nuances of different bounce messages will help you maintain a healthy email sending reputation and ensure your messages consistently reach the inbox. If you are experiencing frequent bounce messages, it might be an indication to review your email deliverability strategy.
Google.
Dropbox, or 
OneDrive, and then share the link in your email. This bypasses the size limit entirely and often ensures quicker delivery.
