POPFile is proxy so cannot redeliver a message to your mail client. It is only able to modify messages by adding headers or tagging the subject as the messages are originally downloaded. There are two main reasons people ask for this feature:
1. To have the message delivered to the correct folder automatically when reclassified. A possible work around is to use POPFile's experimental IMAP module if your email server supports IMAP. This changes the way you and your mail client interact with POPFile, making reclassification as easy as moving the message to the correct folder in your mail client.
2. To recover a lost message. This can also be worked around. All messages that are still in POPFile's history are stored on your hard drive. You just need to locate them and find your lost message.
You can't just copy and paste the message from POPFile's message view if there is an attachment since that will corrupt the file.
The Windows version of POPFile normally stores messages inside a 'POPFile' folder in your Windows user directory but sometimes a different location will be used. Since the location of this POPFile data is not fixed the installer installs a small utility (pfidiag.exe) and a Start Menu shortcut to help you find POPFile's “User Data folder”:
Start -- Programs -- POPFile -- Support -- PFI Diagnostic utility (simple)
On some systems this POPFile “User Data” is in a hidden folder so the installer also provides a “Create 'User Data' shortcut” entry in the same section of the Start Menu to make it easier to access this folder.
In Windows XP the default location for the POPFile “User Data” is something like:
C:\Documents and Settings\User Name\Application Data\POPFile
Under that folder is a 'messages' folder containing a bunch of numbered folders which eventually lead to messages stored in plain text. Each message is stored as a separate file, with names like popfile59.msg, popfile5a.msg, popfile5b.msg, etc.
The easiest way to find your lost message is to use Windows Search. Search for All Files for filename *.msg with “a word or phrase” that appears in one line in the email. Then copy that file and rename the new copy to .EML (for Outlook Express or Thunderbird) and you should be able to open the message in many mail clients. Depending on your mail client though, it may not be possible to then file the opened mail into your inbox.
If all you want is the attachment, you may be able to use PKZIP, WinZip or other extractor that supports UUEncoded attachments to extract it from the .MSG file.