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SMTP Email Error 552 5.3.4 - How to Resolve [SOLVED]

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    Email is one of the critical components of modern communication. The emails are sent and received using Simple Mail Transfer Protocol that allows the emails to be directed to the correct server of the recipient before the message is delivered. This is necessary for seamless communication of the messages. However, challenges could affect the system such as SMTP Email Error 552 5.3.4.

    SMTP Email Error 552 5.3.4 appears as a message rejection or inability to send the email. This problem arises when the email cannot be received but showing that it was sent. The issue arises from the email attachment size limitation or violations such as spam. Moreover, as seen later in the paper SMTP Email Error 552 5.3.4 indicates potential email server issues that may include misconfigurations or reinforcement of the policies, which could affect the overall email send configurations. Therefore, understanding the error problem is necessary to ensure communication.

    Demystifying SMTP email error 552 5.3.4

    SMTP Email Error 552 5.3.4 can appear slightly differently depending on the email client or server in use, but the message typically indicates that the email cannot be delivered due to a size limit. For instance, in Microsoft Outlook, users might encounter a notification such as “552 5.3.4 Message size exceeds fixed limit,” while Gmail users could see “Message rejected. Size exceeds maximum permitted.” These error messages are direct and inform the sender that their email has not been sent.

    Implications of SMTP Email Error 552 5.3.4 on Email Sending

    • Disruption of Communication. This error prevents the email from being delivered, which can interrupt timely communication, especially in professional or urgent contexts.
    • Need for Content Adjustment. Senders are required to modify the email content, typically by reducing the size of attachments or splitting the content into multiple messages, to comply with server limitations.
    • Server Policy Awareness. This error underscores the importance of being aware of and adhering to the specific mail server policies regarding email size, which can vary widely between different email providers or organizational email servers.
    • Potential for Data Loss. In scenarios where large files need to be shared, this error could lead to challenges in data transfer, pushing users to find alternative methods to share large files.

    Exploring the reasons behind SMTP email error 552 5.3.4

    Exceeding Size Limits

    Most email servers have a maximum size limit for emails, which includes both the body of the message and any attachments. When the combined size exceeds this limit, the server rejects the message, resulting in Error 552 5.3.4. These limits are put in place to manage server resources effectively and to prevent system overloads.

    Large Attachments

    It is the primary reason for emails going over the limit due to significant attachment sizes. For instance, high-quality photos, large document owners, or videos will make it impractical to comply with the email server’s limit.

    Embedded content in the email

    In addition to attachments, embedding images or other media in the email will increase its size. More specifically, emails are well-formatted with HTML and extensive inline styling or embedded media.

    Server Configuration

    This issue may also be caused by the particular setup and rules of an email server. The size limitations of servers may differ depending on their specifications and the rules set forth by the hosting company or service.

    Data Accumulation

    An email’s size may occasionally grow unexpectedly due to the accumulation of header data from several forwarding instances or additional metadata.

    Detailed solutions for resolving SMTP email error 552 5.3.4

    Instructions for Gmail users

    1. Check email size. It should not exceed 25 MB in total, including attached files. This is Gmail’s maximum allowable email size limit.

    2. Compress the attached files. To do this, you will need to create a ZIP archive for the file that you intend to attach to the email.

    3. Use Google Drive. If the attached file is more than 25 MB, it would be better to upload the file to Google service and send the link to it in the email.

    For Outlook Users

    1. Verify Attachment Limits. Firstly, make sure the size of the email file does not exceed 20 MB if you use Outlook with internet accounts since it can be less or more for specific enterprise setups.

    2. Compress Larger Files. For larger documents or pictures, it is possible to compress them before attaching files.

    3. Finally, adjust Outlook Settings. A user can also change the default server time out in Outlook so the large attached file can be sent because the longer time means less possibility of error.

    For Yahoo Mail Users

    1. Limit Email Size. Ensure email size is no more than 25 MB, including attachments to fit Yahoo email limits.
    2. Compress Files. Use file compression software to minimize the size of the attachments you are intending to email.
    3. Break Down Large Emails. Split the attachments into smaller parts if they are too large and email each in different messages as needed.

    General Tips

    1. Remember to always verify the recipient’s email capabilities as well, since certain email systems may have more stringent attachment sizes.
    2. When data security and secrecy are critical, think about using secure file transfer services or other alternate means when exchanging huge files.

    Optimizing email management with Warmy.io

    warmy email deliverability

    To prevent SMTP Email Error 552 5.3.4 when sending emails, one can implement email warm-up services like Warmy.io. This service helps users send numerous emails without the recipients’ servers rejecting them due to exceeding an email size limit or other factors.

    Specifically, Warmy.io increases your email volume allowing you to create a sender reputation where your emails will not be rejected specifically for being too large.

    In addition to this, this service provides free deliverability tools such as a tool to check if your emails can be delivered to the recipient’s server, a tool to check if your domain is put on a blacklist, and a tool that generates SPF and DMARC records.

    Therefore, these tools can be used for more than just troubleshooting and resolving deliverability problems – they can also assist in maintaining email performance so it doesn’t deteriorate due to neglecting to comply with best practices archetypical of an already established sender.


    In conclusion, it is important to note that addressing SMTP errors such as Error 552 5.3.4, among others, is a part of the practical maintenance of your email infrastructure. They can lead to a disruption in your email sending and drastic delays in your communication that can have a devastating effect on your business process, customer relations, and more.

    To avoid it, regular monitoring and management of your email parameters based on your ESP requirements and environmental protocols is essential. By actively enforcing your parameters and integrating tools such as Warmy.io, you can cover your email sending and ensure your security.

    👉 Read also – SMTP Email Error 552 – How to Resolve [SOLVED]

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