How to Correct the 'Who' Field when Transferring Mbox E-mail to Eudora

The Problem

When transferring stored e-mail mailboxes from other e-mail clients into the Eudora e-mail client, the 'Who' field in the message list often uselessly shows one's own e-mail address instead of the address one sent to or received from.

[Spelling note to please search engines: This page is anent email. I spell it with the hyphen but it is the same thing.]

The Cause

Eudora stores e-mails in a format very similar to the long used standard Unix mbox format. It is so similar that one can transfer files of e-mails (called a mailbox, mail box or mail folder depending on the client) from many other e-mail programs simply by copying the files to Eudora's directory, renaming its file extension to '.mbx' and restarting Eudora. I do this myself because I use Kmail 1.5 on Linux and Eudora Lite 5 on Microsoft Windows and merge the saved mail to an archive. The archive is in Eudora because, unlike Kmail, Eudora allows me to edit received mail to remove the unnecessary parts (like complete copies of my own e-mails appended to replies).

When listing the e-mails in a mailbox, Eudora conveniently merges the 'To' & 'From' fields into a single 'Who' field which shows 'To' for sent e-mails and 'From' for received ones. Unfortunately when e-mails are imported by copying an mbox mailbox from another e-mail program, it typically uses the 'From' address for sent as well as received e-mails so one cannot tell to whom one sent e-mails from the listing as they all labelled just as being from oneself.

The reason for this is that Eudora does not compare the 'From' address with ones own address(es) to distinguish sent e-mail from received e-mail but uses a separate record. These records are stored in the '.toc' files which act as index files for the '.mbx' files. Although Eudora automatically generates '.toc' files when it finds a newly added '.mbx' mailbox, it does not sensibly generate the appropriate sending information. Instead it merely assumes that all e-mails were received ones unless the mailbox was called 'Out.mbx', the combined out, drafts & sent-mail mailbox, in which case it assumes they were all sent ones.

One could write or find a program to correct the '.toc' files but the problem can be solved without any extra application software by temporarily renaming the mailbox files.

The Solution (Avoiding the Problem)

Before copying the mailboxes from the other e-mail client, use that client to move your sent & received e-mail into separate mailboxes.
If Eudora is running, exit it.
If there is any e-mail in your Eudora 'Out' mailbox, copy or rename your Eudora 'Out.mbx' & 'Out.toc' files to somewhere safe.
Copy the sent mailbox file you want to import into the Eudora folder and rename it 'Out.mbx'. If 'Out.toc' exists, delete it.
Copy the received mailbox file you want to import into the Eudora folder and rename it '<something>.mbx' where <something> is any name you choose other than 'Out', 'In' or 'Trash'. If '<something>.toc' exists, delete it.
Run Eudora. It should automatically generate the missing '.toc' files with the correct sending direction information included.
Within Eudora, transfer the e-mails from the mailboxes '<something>' and 'Out' to whatever mailbox you want them in. The sending direction information should be transferred with them. Delete '<something>' if it is no longer needed.
If you had saved a non-empty Eudora 'Out' mailbox then retrieve it by (after ensuring that all wanted e-mail has been transferred out of the new 'Out' mailbox) exiting Eudora, replacing the new 'Out.mbx' & 'Out.toc' files with your saved previous ones and restarting Eudora.

The Solution (Correcting Sent E'mails to Show To Address)

If there is any e-mail in your Eudora 'Out' mailbox, exit Eudora and copy or rename your Eudora 'Out.mbx' & 'Out.toc' files to somewhere safe then restart Eudora.
Within Eudora, create a mailbox called '<something>' where <something> is any name you choose other than 'Out', 'In' or 'Trash'.
Select the problem e-mails (they are easy to find by sorting by 'Who' and looking for the blocks where 'Who' is your own e-mail address) and transfer them to the '<something>' mailbox.
Exit Eudora, delete '<something>.toc', delete 'Out.toc', rename '<something>.mbx' to 'Out.toc' & restart Eudora. It should accept the new mailbox as being the 'Out' mailbox and automatically regenerate the missing '.toc' file but with the correct sending direction information included.
Within Eudora transfer the e-mails from the mailbox 'Out' to whatever mailbox you want them in. The sending direction information should be transferred with them.
If you had saved a non-empty Eudora 'Out' mailbox then retrieve it by (after ensuring that all wanted e-mail has been transferred out of the new 'Out' mailbox) exiting Eudora, replacing the new 'Out.mbx' & 'Out.toc' files with your saved previous ones and restarting Eudora.

The Solution (Correcting Received E'mails to Show From Address)

Within Eudora, create a mailbox called '<something>' where <something> is any name you choose other than 'Out', 'In' or 'Trash'.
Select the problem e-mails (they are easy to find by sorting by 'Who' and looking for the blocks where 'Who' is your own e-mail address) and transfer them to the '<something>' mailbox.
Exit Eudora, delete '<something>.toc' & restart Eudora. It should automatically regenerate the missing '.toc' file but with the correct sending direction information included.
Within Eudora transfer the e-mails from the mailbox '<something>' to whatever mailbox you want them in. The sending direction information should be transferred with them.
Delete the '<something>' mailbox if it is no longer needed.

Other Possible Eudora Mbox Problems

There are two other ways in which Eudora's mbox files differ from Kmail's mbox files:

Eudora stores attachments as separate files pointed to by an extra field added to the stored e-mail whereas Kmail stores attachments MIME encoded within the stored e-mails. These attachments within e-mails will look like mass of garbage text when viewed in Eudora. However, I don't keep attachments in my e-mail archives so this is not a problem for me.
E'mails are separated in an mbox file by starting each e-mail with a line starting with 'From '. In Kmail this is followed on the same line by the From address whereas Eudora uses a dummy '???@???' address. Eudora then follows it with the sending date instead of putting that in a separate Date field for sent e-mail. This is not a problem for transferring from Kmail to Eudora.
Different operating systems use different ways of denoting line-breaks in text files. Microsoft Windows uses a carriage return character followed by a line feed character, Unix uses just a line feed and Mac OS uses just a carriage return.

Removing the attachments from mbox files before transfer can be tedious as no GNU/Linux e-mail clients I have found have allowed editing of either received or sent e-mail (although not only Eudora but even the notorious Microsoft Outlook can do it on Win32) so it needed a cumbersome & risky editing of the mbox file in a text editor. However I found (just after having wasted time writing a simpler version myself!) a program to do it. 'Delatt' is a Perl program that will remove (or extract) attachments from mbox & maildir mailboxes. It is available from the Delatt's author's website and the Delatt Freshmeat project pages.

I have not tried copying e-mails the other way, from Eudora to Kmail, but the free program Eudora2Unix looks like it will do the job of mbox corrections automatically. It is available from the Eudora2Unix project pages on Sourceforge.

As for the line break problem, if it occurs, that can be cured by a simple search & replace throughout the mailbox file. One can use a text editor, a word processor, a special program or a single-line scripting-language program to do that. It is best to do it before merging the mailboxes to avoid the risk of a too unspecific search & replace job replacing the line feeds (or carriage returns) in that are already in carriage return line feed pairs as well as those intended.