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Error logs

The Customers Mail Cloud identifier can be used to analyze the SMTP error, also known as the bounced mail. You can use the identifier to understand the reason for the error by looking at the groups that each error is classified into. Groups consist of unknown user, unknown host, and more.


The retention period for error logs is 40 days. Logs older than this cannot be viewed.

Checking the logs

  1. Click the Delivery Report in the management console.

  2. You can choose the target server configuration from the list on the left. If you would like to display logs per API user click on the plus + button in server configuration and open this list. It is also possible to choose the target API user.

Error logs

  1. Click the Error Log

    error log

  2. Enter the destination email address or part of it, and click the Search button to search and display the error reason for the corresponding email.

    Display Name Description
    Date Displays the date record of the error status.
    Destination Address Displays the destination address.
    Subject Displays the subject of the mail.
    Error Reason Displays the error reason

Error log details

Additional detailed information can be displayed by clicking on the destination address link.

delivery details dialog

Display name Description
Date Displays the daily record of the error status.
Error Displays the error message.
Sender address Displays the from address in head of error mail.
Return-path Displays the return email address of the bounced mail.
Destination Address Displays the To address in head of error mail.
Subject Displays the subject in head of the error mail.
Message ID Displays the Message-ID in head of the error mail.
X-Api-Data Displays the X-Api-Data in head of the error mail.
Response Message Displays the information of the bounce mail & SMTP message responsed by destination server.

Searching logs

Error logs can be searched using the following parameters:

Parameter Description
Start Date Specifies the error log search history in the YYYY-MM-DD format.
This parameter is mandatory.
End Date Specifies the error log search history in the YYYY-MM-DD format.
This parameter is mandatory.
Error Specifies the error message to be searched
Destination address Search the part of destination mail address inputted by partial match.


If the number of search results exceeds 100, the first 100 results will be displayed.Please specify the destination address, period of time, and error reason as search conditions to narrow down the search target data.


Paging is performed when the number of search results exceeds 10. Please use the pager at the top right of the search results list to browse.

Downloading logs

You can download the error log search results as CSV file by clicking the Download button.

download dialog


This function is disabled as a default. If you want to use this feature, please request from the inquiry form in the management console. When it turns enabled, other download functions (error log, delivery blocking) are also enabled.


Even if you have more than 100 search results, you can download the data of all the results. The character code of the CSV file is UTF-8, and the line feed code is LF.

The below information will be displayed in downloaded CSV files.

Item name Description
received Record date of error status.
status digit of error status
from From address in header of the destination mail.
to To address in the destination error.
message ID Message ID in the header of the destination mail.
error Information of bounced mail and SMTP message response by destination server.