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Backed Up Mail - Unsent Mail Guide

※ Last updated: 2025-09-08

SHIELD Mail'sUnsent MailThe menu is a screen where you can check and manage emails that encountered errors during the sending process and were not successfully delivered externally. These emails are stored for a maximum of 2 months and will be automatically deleted thereafter.

1. What is an unsent email?​

**What is an Unsent Email?** An unsent email refers to an email that has successfully undergone conversion but failed to be delivered to the recipient due to an error that occurred during the delivery process.

  • Transmission Path: SHIELD Mail → External Mail Server
  • Causes of failure: conversion errors, mail server errors, etc.
  • The reason for non-delivery can be checked in detail along with the error code.

2. Menu Entry​

Backed Up Mail > Unsent MailYou can access the untransmitted email management screen from the menu.

unsent-mail

  • You can select a period (7 days, 30 days, 45 days, 60 days) and a custom period at the top of the screen.
  • SIDYou can search for specific emails by entering keywords for the sender/recipient.

3. Screen Composition​

3-1. List Table Items​

ColumnDescription
dateDate and time when the email was attempted to be sent
Error TypesReasons for Transmission Failure
SenderSender's email address
RecipientRecipient's email address
TitleEmail Subject
SIDUnique identifier assigned by the system (Session ID)

3-2. Detailed View​

When you click an item in the list, detailed information is displayed in the right panel.

unsent-detail

  • Transmission Error Information Tab

    • date
    • Transmission Error Types
    • Error Codes and Detailed Messages

  • Details Tab

    • Sender / Receiver
    • SID
    • Title
    • Attached file name

3-3. Unsent Error Types​

The types of errors that can be confirmed in unsent emails are as follows:

① Errors related to PEP file conversion

  • Conversion result error
  • File conversion error
  • Error in generating EML based on conversion file

② Transmission-related errors

  • Mail server related errors
  • Email Sender Related Errors
  • Email Recipient Related Error
  • EML transmission error
  • Unknown error

③ Reception-related Errors

  • EML Receiving Error
  • EML File Creation Error
  • EML Parsing Error (Format Error)
  • EML Limit Error (Mail Size, Maximum Hop, etc.)
  • Queue file creation error

Scheduled for update.