The PCMech Premium members have read (and seen in video) in great detail the lengths I go to to instruct how to archive email, be it POP, IMAP, Hotmail, Gmail, Yahoo Mail and so on.
This article however is a freebie because it involves now-ancient mail data formats and how to convert them to modern format. And I know there are some poor souls out there still using these format types, so hopefully after reading this they will upgrade to something better like Mozilla Thunderbird, Windows Live Mail or a current version of Microsoft Outlook.
And if you hate email clients, once you pull mail into a client you can push it over to Gmail (IMAP/any modern mail client) or Hotmail (DeltaSync/Windows Live Mail) afterwards.
The two ancient formats I will speak of are Eudora and pre-2003 Microsoft Outlook PST archives. Very recently I discovered I had email archives on CD dating all the way back to 2001 which used these two formats. I wrote about this on my personal site, so I can speak first hand on how the conversions work.
Eudora to Thunderbird
Believe it or not there are those who still use Eudora and absolutely positively refuse to give it up (much like Microsoft Outlook users). They are affectionately called "Eudorka" users.
Eudora has an interesting way of storing mail, because if any mail contains a file attachment it is not stored within the individual emails themselves but rather a separate directory called "attach". This is not as odd as you would think because computers back then were slower, and separating the attachments from the mail itself actually worked better as it took less system resource. This is part of the reason Eudorka people love the client so much.
The easy way
Use Mozilla Thunderbird. It has built-in import support for Eudora import. However it will not grab the file attachments. Not with Eudora 5.1, anyway.
The hard way
On a Mac: Eudora Mailbox Cleaner
On Windows: Eudora Rescue
Both of these will convert to a more modern mbox format that Thunderbird can import easily including all the file attachments. But neither are easy to use. Works, yes, but not easy.
Microsoft Outlook PST to Windows Live Mail
The deal with Outlook PST files is that the pre-2003 Outlook client has a maximum allowed PST size of 2GB. Those who have worked in tech support long enough are quite familiar with the Inbox Repair Tool, a.k.a. scanpst.exe to fix/repair the stupid thing whenever it reaches its cap.
Outlook 2003 to present version on the other hand has a 33TB PST file size limit using the modern unicode format. Huge difference. There is no automatic way to convert an old PST to the current unicode one. But you can perform an import. More on that in a moment.
The easy way
Assuming you’re using Windows XP, if you already have Outlook 97 to 2000 installed (why you’re using something that old I have no idea), have Outlook Express 6 import all your mail. Go into Outlook Express, click File, Import, Messages, select Microsoft Outlook and it’s a done deal.
After that, run Windows Live Mail and click File, Import, Messages and pull in all your mail from Outlook Express 6. Works like a charm. After that, go back to OE6 and delete all the mail out of there since you’ll be using WLmail.
The hard way
Buy a new copy of Outlook, perform an import from the old PST to a new unicode version which the current Outlook creates by default. Remember, there is no automatic conversion from old-to-new PST. You must import from the old to the new manually. I label this as the hard way because you have to flip out cash to do it. Otherwise it’s easy.
Q: Can you convert a Microsoft Outlook pre-2003 PST without Outlook?
A: No. It’s a protected format by Microsoft. There is no known utility (none that I know of anyway) that will convert a PST without having Outlook physically installed. You absolutely must do it the Outlook way.
This, by the way, is a huge reason I am very anti-Outlook. I have never liked the fact that everything you do in a local Outlook database is one big honkin’ proprietary file that cannot be worked with unless you specifically have the Outlook client installed.
Should you fear that the email client you upgrade to will become obsolete?
All software inevitably becomes obsolete. What you have to do is use software that is continually developed with newer versions over time that you either upgrade to for free or purchase when needed.
If you use Microsoft Outlook, yes you will have to buy a new version of it every few years and there’s no way around that. And as long as Microsoft exists and people store data locally, there will be Outlook. It will be around a long, long time.
If you use a free mail client, you will have to periodically download and install an upgrade it when new versions are released. Mozilla Thunderbird/SeaMonkey is actively developed, as is Apple Mail and Opera’s built-in mail client. Ones that have active development and widespread use will stick around for a long time.
Is the email client on the deathbed?
No. Not by a long shot. The day we have no more email client programs is the day we have flying cars. Just stick with a current version of an email client and you’ll be a-okay.
To you Eudorkas out there, don’t go with Penelope. For the love of creamed corn and Christmas, use Thunderbird.

Why no Penelope? (Not running Eudora here, but it seems to be a good option for those that are).
Mainly because it’s not much more than Thunderbird just made to look/act like Eudora did. You’re better off just using t-bird outright.
Sorry… guess I’m one of your diehard “Eudorka” users. I’ve been using it for the past 15 years and still love it.
I’ve used Thunderbird, and have the latest version installed, but will only leave Eudora ‘kicking & screaming.’ Eudora manages my 15 household email addresses, across five ISPs, perfectly. More important, I have 6 systems at home that I keep synced (3 desktops; 3 laptops). When originally setting them up, all I do is install Eudora & then copy the “C:\Program Files\Eudora” from one of my previous PCs on top of the newly installed Eudora directory, and WA-LA! My new system has all my ISP email account settings, along with the previous 12+ years of email. This feature alone I find the most important. And even with keeping all my old email, Eudora runs just as fast as ever. I especially like the storing of attachments separate from the individual emails, in their own folder. I also love the fact that the mailbox files are just “text” files. For non-html emails, they are very readable in any text editor.
As for Outlook? Blahhhhhhh. I’ve never liked it, even tho’ I’ve been forced to use it @ work for over 10 years. Windows Live? Never tried it (& never will, if I have a choice).
Thunderbird? Great program, and that’s what I’ll switch to full-time when Eudora no longer runs. Does anybody know — can you “clone” Thunderbird from one PC to another as easy as Eudora (with all acct settings & email)?
If you copy the profile directory from one Thunderbird installation to the other, yes. If you want everything in addition to all mail (plugins, Lightning calendar, etc.), use KLS Mail Backup to transfer from one to the other using a single ZIP.