How does Aid4Mail 4 detect duplicates?

Aid4Mail checks for email duplicates by comparing the value of the Message-ID field in each processed email header.

If this field is empty or missing (usually in outbound messages), Aid4Mail uses the email date and subject line for the comparison, or the whole message header if either of those values are blank. With MAPI messages (from Office Outlook or MS Exchange) however, Aid4Mail uses the email creation and submit dates, subject line, and stored message size for the comparison.

When extracting attachments and other embedded contents, Aid4Mail first checks if a file with the same name exists in the target folder. If there is, it checks whether the contents are identical. If they are, the duplicate is not saved. If the files are different, then Aid4Mail saves the file with a new name – the original filename followed by an index number in square brackets. Example:

  • Untitled.doc
  • Untitled[1].doc
  • Untitled[2].doc


If you experience any issues, please don't hesitate to contact us.

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