Remove Duplicate Messages

Summary: Removes duplicate e-mail messages from a mailbox.
Requires: EagleFiler 1.6.6
Install Location: ~/Library/Scripts/Applications/EagleFiler/
Last Modified: 2026-02-08

Description

This script scans the selected mailboxes in the records list or the source list. (Prior to EagleFiler 1.7, the mailboxes must be selected in the records list; with 1.7 or later, the script will use whichever list has focus.) If a mailbox contains duplicate copies of the same e-mail message, the script creates a new mailbox with the duplicate e-mails removed. (If your duplicates are spread across multiple mailboxes or are stored in .eml files, you should first merge them.) It then moves the original mailbox to the trash. This script has the following limitations:

Mailboxes of a few MB will be processed very quickly. For large mailboxes, the script may take a long time to run. It does not report on the progress while it’s running. If you are wondering whether the script is still doing anything, you can watch the “formail” process in Activity Monitor. To help determine what performance you should expect, here are some processing times from a 2012 Retina MacBook Pro:

Installation Instructions · Download in Compiled Format · Download in Text Format

Script

tell application "EagleFiler"
    try -- requires EagleFiler 1.7
        set _records to current records of browser window 1
    on error
        set _records to selected records of browser window 1
    end try
    set _mailboxes to {}
    repeat with _record in _records
        if my isMailboxRecord(_record) then
            copy _record to end of _mailboxes
            my removeDuplicatesFromMailboxRecord(_record)
        else
            my showAlert("Skipping File", "Skipping “" & _record's filename & "” because it is not a mailbox.")
        end if
    end repeat
    if _mailboxes is {} then
        my showAlert("You did not select any mailboxes.", "Please click on Records or a folder in the source list (at the left) and then select one or more mailboxes in the records list (at the top-right).")
    end if
end tell

on isMailboxRecord(_record)
    tell application "EagleFiler"
        if _record's universal type identifier is "com.c-command.mail.mbox" then return true
        return false
    end tell
end isMailboxRecord

on removeDuplicatesFromMailboxRecord(_record)
    tell application "EagleFiler"
        set _file to _record's file
        set _path to _file's POSIX path
        set _filename to _record's filename
        set {_newPath, _count} to my removeDuplicatesFromPath(_path)
        if _count is 0 then
            my showAlert("No Duplicates Found", "There were no duplicate messages in “" & _filename & "”.")
            return
        end if
        with timeout of 24 * 60 * 60 seconds
            tell _record's library document
                set {_newRecord} to import files {_newPath}
                my copyMetadata(_record, _newRecord)
                set container of _record to trash
                set _newRecord's filename to _filename -- Wasn't possible to set it correctly earlier.
            end tell
        end timeout
        my showAlert("Duplicates Removed", "Removed " & _count & " duplicate messages from “" & _filename & "”.")
    end tell
end removeDuplicatesFromMailboxRecord

on removeDuplicatesFromPath(_sourcePath)
    set _tempFolder to my makeTemporaryFolder()
    set _cachePath to _tempFolder & "/" & "idcache"
    set _destPath to _tempFolder & "/" & "NewMailbox.mbox"
    set _logPath to _tempFolder & "/" & "Log.log"
    -- cat Old | perl -p -e 's/\r\n/\n/g' | perl -p -e 's/\r/\n/g' | formail -b -e -q- -Y -D 104857600 idcache -s > New
    set _script to "cat " & _sourcePath's quoted form
    set _script to _script & " | perl -p -e 's/\\r\\n/\\n/g'"
    set _script to _script & " | perl -p -e 's/\\r/\\n/g'"
    set _script to _script & " | " & my formailPath() & " -b -e -q- -Y"
    set _script to _script & " -D 104857600 " & _cachePath's quoted form -- 100 MB
    set _script to _script & " -s > " & _destPath's quoted form
    set _script to _script & " 2> " & _logPath's quoted form
    with timeout of 24 * 60 * 60 seconds
        do shell script _script
    end timeout
    set _count to my countDuplicatesFoundFromLogPath(_logPath)
    my reportErrorsFromLogPath(_logPath)
    return {_destPath, _count}
end removeDuplicatesFromPath

on countDuplicatesFoundFromLogPath(_logPath)
    set _script to "grep -c \"^formail: Duplicate key found:\" " & _logPath's quoted form
    try
        set _stdout to do shell script _script
    on error number 1
        return 0
    end try
    return _stdout as number
end countDuplicatesFoundFromLogPath

on reportErrorsFromLogPath(_logPath)
    -- Skip lines starting with "<" becuase they are probably a wrapped message ID
    set _script to "grep -vEc \"^(\\s*<|formail: Duplicate key found:)\" " & _logPath's quoted form
    try
        set _stdout to do shell script _script
        set _errorCount to _stdout as number
    on error
        set _errorCount to 0
    end try
    if _errorCount > 0 then
        do shell script "open -a Console " & _logPath
        set _title to "Possible Errors Reported"
        set _message to (_errorCount as string) & " unexpected log entries were found when processing the mailbox. Please review them in Console."
        with timeout of 24 * 60 * 60 seconds
            display alert _title message _message buttons {"Cancel", "Ignore the Errors"} cancel button 1
        end timeout
    end if
end reportErrorsFromLogPath

on makeTemporaryFolder()
    return do shell script "mktemp -d -t 'EFRemoveDuplicateMessages'"
end makeTemporaryFolder

on copyMetadata(_source, _dest)
    tell application "EagleFiler"
        set _sourceURL to _source's source URL
        set source URL of _dest to _sourceURL
        set container of _dest to _source's container
        set _noteText to _source's note text
        set note text of _dest to _noteText
        set _tags to _source's assigned tags
        set assigned tags of _dest to _tags
        set _title to _source's title
        set title of _dest to _title
        set _fromName to _source's from name
        set from name of _dest to _fromName
        set _labelIndex to _source's label index
        set label index of _dest to _labelIndex
        set _creationDate to _source's creation date
        set creation date of _dest to _creationDate
        set _modificationDate to _source's modification date
        set modification date of _dest to _modificationDate
    end tell
end copyMetadata

on showAlert(_title, _message)
    with timeout of 24 * 60 * 60 seconds
        display alert _title message _message buttons {"Cancel", "OK"} cancel button 1
    end timeout
end showAlert

on formailPath()
    -- Prior to Mac OS X 10.11, it's also available at /usr/bin/formail.
    set _path to path to application "EagleFiler"
    set _posixPath to POSIX path of _path
    return _posixPath & "Contents/Frameworks/WashFramework.framework/Versions/A/formail"
end formailPath