Resolving the "552.5.3.4 Your Message Exceeded Google's Message Size Limits" Error

Overview

This article explains why you might receive the error message "552.5.3.4 Your message exceeded Google's message size limits" when sending emails, particularly to Gmail addresses. It covers the causes of the error, details Gmail's size restrictions, and offers practical solutions to prevent this issue.

What Does the Error Mean?

The error indicates that the total size of your email—including any attachments—exceeds the limits imposed by Google's email servers. When an email is too large, Google's systems reject it to maintain performance and security standards.

Gmail's Email Size Limits

• 25 MB Maximum Size: Gmail has a hard limit of 25 MB per email message. This size limit applies to the entire email, including attachments.
• Encoding Overhead: Email attachments are typically encoded using methods like base64. This encoding increases the overall size by about 33%. For example, an attachment that is slightly less than 25 MB in its original format might exceed the limit once encoded.

Why It's Not an SMTP Server Issue

Even if you are using your own SMTP server to send emails, the error is generated by Google's servers when they receive the email. Therefore, this is not a problem with your SMTP server, but rather with the size of the email relative to Google’s limits.

Common Scenarios

• • Large Attachments: Sending files such as high-resolution images, videos, or large documents often causes this error.
  • Multiple Attachments: Even if individual attachments are below the limit, their combined size (after encoding) might exceed 25 MB.
  • Email Thread Overload: Sometimes, including multiple replies or forwards with accumulated attachments can push the overall size over the limit.

How to Resolve the Issue

1. Reduce File Sizes

• • Compress Files: Use file compression tools (e.g., ZIP or RAR) to reduce the overall size of your attachments.
  • Optimize Content: For images, use lower resolution versions; for documents, remove unnecessary embedded media.

2. Use Cloud Storage Services

• • Upload Files: Instead of attaching large files directly, upload them to a cloud storage service such as Google Drive, Dropbox, or OneDrive.
  • Share Links: Include a shareable link in your email. This approach not only circumvents the size limits but also provides a more efficient way to manage file distribution.

3. Split the Email

• • Multiple Emails: If possible, send the attachments in multiple emails rather than bundling everything into a single message.
  • Segment Information: Consider splitting the content logically across several emails if it makes sense from a communication perspective.

Best Practices

• • Check Attachment Sizes: Before sending, verify that the total size of your attachments (after considering encoding overhead) is well below 25 MB.
  • Inform Recipients: If you plan to use a cloud storage link, provide clear instructions to your recipients on how to access the files.
  • Monitor Email Threads: In ongoing conversations, be mindful of the cumulative size of attachments in email chains.

Conclusion

The "552.5.3.4 Your message exceeded Google's message size limits" error is a common issue when large files are sent via email. By understanding Gmail's 25 MB limit and the additional size increase from encoding, you can take proactive steps to reduce email size, use cloud storage for larger files, or split the content across multiple emails. Following these practices will help ensure your emails are successfully delivered without encountering size limit errors.

For further assistance, please contact technical support.