"Too Much Mail Data" Error Explained


This document provides guidance on the "Too much mail data" error encountered in ImprovMX. This error typically occurs when the size of an email exceeds the allowable limit. Understanding the limits based on your subscription tier can help you manage and avoid this error effectively.

Error Explanation

What is the "Too Much Mail Data" Error?

The "Too much mail data" error in ImprovMX is triggered when an email's size surpasses the maximum limit allowed by your current subscription tier. This error prevents the email from being forwarded or received, ensuring that the system's performance remains optimal for all users.

The error is normally seen by the sender of the email as part of the Non-Delivery Report (NDR) / bounceback but it can also be seen in your ImprovMX logs, available via the Dashboard.

Subscription Tiers and Size Limits

  • Free Tier: The maximum email size is 10MB.

  • Premium / Enterprise Tiers: The maximum email size is increased to 50MB.

Emails exceeding these limits will result in the "Too much mail data" error.

Causes of the Error

Several factors can contribute to an email exceeding the size limit:

  • Large Attachments: Files such as images, documents, or videos can significantly increase the email size.

  • Rich Media Content: Emails with embedded media, like images or HTML content, can also be substantial in size.

  • Extended Conversations: Long email threads with multiple replies and attachments can accumulate to exceed the limit.

Solutions and Recommendations

For Free Tier Users

  1. Reduce Attachment Sizes: Compress large files before attaching them to your email. Many online tools are available to compress images, PDFs, and other file types.

  2. Use External Links: Instead of attaching large files directly, consider uploading them to a cloud storage service (e.g., Google Drive, Dropbox) and sharing the link in your email.

  3. Upgrade 🙂: Upgrading to the Premium tier is straightforward and offers additional benefits beyond the increased email size limit. You can do this directly from your dashboard.


By understanding the "Too much mail data" error and the size limits of your subscription tier, you can take proactive steps to manage your emails effectively. Whether you reduce attachment sizes or upgrade to the Premium tier, these measures will help ensure seamless email communication through ImprovMX.

If you have any questions or need additional help, feel free to reach out to our support team at support@improvmx.com.

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