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From Outlook to Thunderbird and Back Again

Outlook ThunderbirdThe process of exporting email from Outlook to Thunderbird on Windows is really easy. Exporting it from Thunderbird and importing in to Outlook is not hard either, just time consuming. Both ways can be done.

Outlook to Thunderbird
This is actually really easy. The first thing you need is all your email in Outlook. Then, when you setup Thunderbird it will ask you if you want to import your Outlook email. Say yes and it does all the work. No, Thunderbird doesn’t have an import function for the PST file, but it can import anything that’s in Outlook on the same machine. It’s as easy as that.

Thunderbird to Outlook
This process is a bit more complex . Outlook doesn’t directly import Thunderbirds email, however with the right tools, and some time, it can be done.

The first thing you’ll need is a program called IMAPSize. It’s a free Windows application that has a built in tool called mbox2eml. This handy program is used to convert Thunderbird’s mbox email files into eml files. The mbox files are found in your Thunderbirds profile folder (usually in the mail -> local folders). If you don’t see any files with the extension mbox, then it’s the ones without an extension.

The downside here is that each folder you have in Thunderbird is a seperate mbox file. You have to convert each one. Anything in a sub folder will have to be converted too and you may start to loose your folder structure. Oh well, you can always put it back together later.

Once everything is in eml format, you must now startup Outlook Express! That’s right, Express. No need to setup an email account in there, but you should setup all your folders to mirror what you had in Thunderbird. Then, open the folders on your computer that were created from the mbox2email tool and drag the individual eml files into the corresponding Outlook Express folders. You can drag and drop as many eml files as you want, but you can’t drag in a folder. Once you’ve copied all your emails into Outlook Express, you can now import them into Outlook.

Startup Outlook, create your profile and once that’s all setup, go to Import/Export, import from another application and choose Outlook Express. If I remember correctly, it first said it couldn’t import the email then it asked me if I wanted to import all the email. I said yes and all the folders and emails were imported into Outlook.

So there you have it. Importing email from Outlook to Thunderbird is pretty simple and importing email from Thunderbird to Outlook can be done. Depending on how many emails and folders you have will determine how much time it will take. Defiantly going from Outlook to Thunderbird is easier and quicker!

For a much more detailed process of moving from Thunderbird to Outlook, check out this great tutorial: Export Thunderbird to Outlook.

51 Responses

  1. jdb says:

    I installed Thunderbird for a client who was using Outlook Express as part of the install it asked do i want to bring over the Address Book, Messages and Settings, I indicated Yes. That took some time, but once completed the messages did not come over and now I cannot find Outlook Express (the program) anywhere on the hard drive and of course lost months of emails!!!

    • Rolf says:

      Do yourself a favor and stop playing with toys that are for big people…
      Uninstall thunderbird, and outlook express will be back.

  2. Thomas says:

    I highly doubt Thunderbird would delete Outlook Express. Something sounds fishy there.

  3. Bruce Southworth says:

    Your description of transferring Outlook to Thunderbird is great – if they happen to be on the same computer. I’m looking for a way to move email from my work laptop to Thunderbird on my home desktop. Any ideas for that? Thanks.

  4. Thomas says:

    Hi Bruce. What email client is your work laptop? If Outlook, can you install Thunderbird on the same machine for conversion purposes? Then move the files home?

  5. Bruce says:

    Not a bad idea – it may be do-able for the short term purpose. Our security conscious IT department frowns on any extraneous software being loaded on corporate computers. Thanks.

  6. Thomas says:

    Or do you have Outlook at home?

  7. Fernando says:

    Outlook to Thunderbird
    I used you suggestion and it appeared to work fine.
    Most of the messages were well converted.
    However, some of the messages are now displayed in html.
    What happened?

  8. gpo says:

    Am looking at installing thunderbird on corporate computers and import outlook express 5 on macos.
    if I import emails from express 5 to TB do I lose any emails from the express 5?
    Whats the pros and cons?

  9. Thomas says:

    GPO, I don’t see any reason why you’d loose emails. Just make backups before syncing to be sure.

    Fernando, I’m unsure about your issue. I’m not well experienced with Outlook.

  10. Ashish says:

    Really helpful decription in exporting from one mail client to other. I just migrated from outlook to thunderbird. Really amusing to play with addons and themes.

    Thanks for this nice explaination.

  11. doez says:

    thank’s BRo

  12. Bruce says:

    Wow, Fred, I bet you feel a lot better now that you’ve purged that!

    I’ll concede your points as they relate to the original article, but I work in the technology field and “setup” and “startup” are often names of procedures or executable files. So there are times when they are appropriately used as nouns. Sadly, there are few things as definitive as you’d like them to be.

  13. princeofmugs says:

    Hey! Great advice.. I’m stuck, however, at the Outlook Express part…. On my Vista laptop, there is no longer ‘Outlook Express’.. it’s been replaced by Windows Live – which just doesn’t seem to cut it.
    Any suggestions about how to proceed from the ’eml’ stage to the importing into Outlook stage without OE? Or is there someway to install OE without screwing up IE? Advice would be spectacularly welcome!

  14. princeofmugs says:

    Don’t mind me… Windows Mail works the same as OE. I’m an idiot.

  15. Jason says:

    There is a good guide on how to convert from Outlook to Thunderbird:


  16. guest says:

    trying to convert from MS Outlook 2003 to Thunderbird (, while the conversion completed succesfully, SOME of my PST folders, although ALL my emails were transfered, when I tried to open the emails, they appearred as HTML and not as text/rich text/word format .

    Any idea on that ? How this can be fixed ?

    Thank you for your time,

  17. Alex Krenvalk says:

    For work with mails and possible other type files,advise try-how to recover .dbx files,tool helped me many times and has many possibilities,also program is free,it supports a great number of features, that turns email into a powerful tool to run business,program analyzes all files of dbx format from Outlook Express root directory and unpacks messages, even if these files are infected or seriously damaged,recover Outlook Express dbx file is compatible with Windows 2003, Windows XP, Windows 2000, Windows NT 4.0, Windows Me and even Windows 98, that is currently not supported by Microsoft Corporation, all versions of Outlook Express are supported.

  18. mutu26 says:

    At work with mails advise try-outlook express dbx extractor,because this tool helped me many times,it can repair mailboxes in Outlook Express format and extract emails, when it is possible,repair messages from all folders and extract .dbx files, even from Deleted Items,moves to the preview mode, where our customers can take a look at the emails, that will be retrieved during the next stage,works with all Windows operating systems, starting from Windows 98 to Windows Vista (Windows 98, Windows Me, Windows NT 4.0, Windows 2000, Windows XP and Windows 2003).

  19. Don says:

    I installed IMAPSize 0.3.6 on Vista Home Premium but when I tried this procedure on TB the result was an empty Inbox folder. I retried and got the same results. Any thoughts.
    Thanks in advancefor your help.

  20. Tamekia Armand says:

    Hi, I cant understand how to add your site in my rss reader. Can you Help me, please 🙂

  21. rbalaji_69 says:

    Hi, Thanks a lot for this information. The process worked like a charm. I tried looking at other sites, but the instructions were not clear. Thanks again. I like the look and feel of outlook better than Thunderbird, even though thunderbird is fast and doesn’t hog memory as outlook.

  22. Veena says:


    I am testing Thunderbird client at work. I imported all mails from Outlook 2007 to TB. All mails are available and did not lose the folder structure of local folders. Some issues i am facing:

    1)I am not able to read many of the mails in local folders as it is in HTML code and not in normal mail message (rich text/text) format. I have to paste mail in notepad and convert to HTML before i can make any sense.
    2)I have set up the GAL in TB. In Exchange, user properties have additional fields for Employee ID etc. which is not available in TB user properties.

    Can someone please suggest a work around?

    Many thanks in advance,

  23. guest says:

    Veena hello,

    please inform us how you make the import form Outlook2007 to TB successful.

    As for the HTML, you may check the properties tab in TB for the specific folders, and make sure the options
    “Apply default to all messages in the folder ….. “, for the encoding IS NOT checked, and that you have use the correcto Default Character Encoding (from the same screen, at the pull down menu)

    See if that helps, and inform us,

  24. Peter Capusotto says:

    I tried the method that you’ve specified and I got a lot of email errors and the need to do it folder by folder is a terrible mess.
    Look this tutorial that I think it’s much better way to do the trick:


  25. Tony says:

    I want my email (on my pc) that run under Ms Outlook to be open in my laptop which use Thunderbird. And want that my existing email in thunderbird join with the ex-Ms Outlook that I want to move. Is it possible?

    Thanks a lot Thomas

  26. Alex says:

    I found the free MBOX to EML Converter tool, it works like IMAPSize but also detects the mbox version and headers type. Nevertheless the mbox to eml extractor is WIN32 utility, it can extract files of eml format from mbox mailboxes created by MAC OS X and Linux / Unix email software.

  27. webwolfe says:

    I installed thunderbird 3.0.4. but on setup it doesn’t ask me to import anything. I tried it twice, once with Outlook closed and once with Outlook open. When i use the import function and choose “import everything” thunderbird continues but shows nothing to import from. If i choose import > email it does work import all my outlook mail. Then i ran import once more to import my contacts.
    I used outlook 2007 to import from.

  28. Shaun says:

    How can I store thunderbird emails in outlook 2010… I have around 10 GB data in thunderbird account?

    Please help if anybody can.

    • Rex says:

      Mate, pain in the arse is what it is. It takes hours believe me. Thunderbird should be making an add-on or incorporating an export method that allows you to export to Outlook but it seems a bit of nazism is going on where they don’t want to do this. Fine for importing, absolute crap for exporting. I now fully regret using thunderbird. Don’t get me wrong, i liked thunderbird 2 because the account options were user friendly. Now some smartarse in their development team has decided everyone obviously must use email like them so they took away the option for POP accounts (automatically makes it imap) and if you don’t know how to change it (you have to stop the account setup at wizard) then it really pisses people off. The to top that off the idiots went and changed the storage options and i for the life of me hate the option because it doesn’t allow you to check a box to “delete messages from server” (like in thunderbird 2). Now we have an ambiguous statement in options that say delete messages from local AND server????????????????? (NOT ONE OR THE OTHER) When something is working donkeys then leave it be. Your going down the road of microsoft who love to play around with setting and changing options. Your going to lose alot of people this way and the only person you can blame will be your IDIOT developer who recommended it.

    • Rex says:

      Go to this link.

      I pity you though if you have heaps of folders and subfolders…………………………

      Does someone from Thunderbird wish to explain WHY they haven’t made an ADD ON that exports messages for Outlook????????? People have been waiting for years and all this non action just proves to me you guys are really not interested in making life easier, just more complicated.

      • nana says:

        Thank U Rex. I need the pity. Piles to move, no good way. Thinking I made a HUGE mistake when I went to TB. Not sure about any of the Firefox stuff anymore. Maybe I can just print all (35,000) and have them filed the old fashioned way. It would take LESS TIME!

  29. Onyx says:

    Thank you for all the suggestions. They helped me with the problem of importing the TB mail messages from a StorageCraft image of the customers old computer HDD into his new PC running Outlook 2007.
    BUT I would appreciate guidance on IMPORTING into Outlook Express or Outlook 2007 a Thunderbird Addressbook. You will all now say easy but please note you do not have the ability to run Thunderbird to perform an EXPORT.
    To get the mail messages across I installed TB and somehow (blindly) eventually managed to get the mail into a TB profile then using IMapSize and finally MBOX2eml managed to get it all into OE. OE to Outlook 2007 is easy and anyone can do that.

    So to summarize:
    New XP PC running Outlook 2007, OE and TB Vers 3.04
    StorageCraft ShadowProtect Image of the old PC. The TB client vers is unknown!
    The mission should you wish to accept it is to get his address book from old TB vers across to Outlook 2007 (eventually) 🙂

  30. Maria says:

    I need to export emails from outlook express on my old computer to thunderbird on new computer. I didn’t have a chance to install thunderbird and transfer mails from OE before my computer crashed. However, I did export emails from OE and saved them on my flash drive they files in .dbx format.
    Any way I can import them for thunderbird?

    • Scott says:

      Found a really easy way to move mail from Thunderbird to Outlook 2010.

      First set up a Gmail or some other IMAP account.
      Set up the account in Thunderbird and in Outlook 2010, this is why Gmail works great.
      Move the saved mail from the Thunderbird saved folders to the Gmail account saved folders.
      Once the mail as moved (it might take a while), close Thunderbird, and open Outlook.
      Sync the Gmail account in Outlook.
      Once the saved mail from Gmail is in Outlook, then move Gmail saved folders to the Outlook personal folders account in the folders you want the saved mail in. This might take some time because the mail as to be downloaded from Gmail in to Outlook.
      The move will save the folder structure.
      Once the saved mail is in the personal folders, you can then move it anywhere you want in Outlook easily.

      This worked great for me, although Outlook did crash 2 times while downloading the files from Gmail.

      Hope this helps someone else.


  31. BB says:

    Thank you!!! After a whole bunch of hassle with other options, I did this in less than 5 minutes. Such relief! (Now I just need to link all the imported messages to their appropriate contact records in BCM — but that’s okay…good music will help. 🙂 )

  32. vl says:

    Aid4Mail Home is able to convert, extract, export, migrate your emails to other email client applications. It supports scripting, the ignoring of duplicates, the usage of email date and content filters.

  33. problem says:

    please help me …… i need best 100% working thunderbird to outlook converter … if u know any one please post the link

  34. John Doffing says:

    Tada ! I haven’t tried it yet, but searching with Bing I found a program called Address Magic Personal Plus at that sounds like it should do the trick. It’s on sale now for $19.98. The web site says it will convert the email, folders, and address book. If it works it’s easily worth $20 just to save time.
    Has anyone tried Address Magic?

  35. T.T. Adom says:

    For Moving over ThunderBird from Outlook, that way is good way but not a best and perfect way when we come in another machine. I was a Outlook user and decided to move my all emails into ThunderBird. Being as a ThunderBird user, i used same way but was unable to retrieve all emails. Making an online hunt was a single way for me and finally i got a very cost effective Outlook Conversion tool. Its converted my all outlook emails into .eml format. After that Darg and Drop was very easy for me.

    Anyone can try this tool if he/she want to save cost. Awesome tool, no arguments!!!

  36. Bruce G. says:

    This is all great, but what about windows 7 where the OE app does not exist? How do I do the move to Outlook 2010?

  37. John Doffing says:

    Hi Thomas, I tried the address magic personal edition program. I did not do the conversion for over a month after purchase. Now I wish I hadn’t waited so long. Address magic did a good job converting my emails. The only down side I’ve found is that it puts my many T-Bird address books into one flat Outlook 2010 address book.
    As far as I can tell all my saved emails, receipts, etc. are intact after the conversion. It did not take very long to run either (at least on my 6-core AMD Phenom II, ?I think this ASUS mboard has 3G Sata so I guess it’s pretty fast).
    I’m used to using Outlook so I prefer it over T-BIrd. I still have Thunderbird installed, just disabled the ISP mail settings, so I can look at the original address books if I need to.
    Good program, Thunderbird ought to include it … wait, Thunderbird is free. Guess that wouldn’t work.

  38. Phil says:

    Everything I’ve read about importing Outlook mail and contacts into Thunderbird makes it sound really easy. But they never, ever talk about whether it deals well with multiple pst files or whether the mail stays in the appropriate folders.
    I have over 4GB of mail sorted into multiple folders in multiple pst files (Outlook isn’t happy when you pst files get over 1GB.) So, before I make that leap (if I do), I’d like to know that everything is going to be in the same place as it is in Outlook. I’m currently on Outlook 2003.

  39. yohan says:

    thanks for sharing this information. i have a damage outlook.pst file . i cannot copy the file for backup my outlook data. but with this method i can backup all my email to thunderbird and back it up to outlook again. thanks bro you save my life.

  40. Touchstar UK says:

    Hi Dude,
    I already installed Thunderbird on my machine and want to get emails in Thunderbird from Outlook 2007. Do you have any idea to import the Outlook 2007 emails in Thunderbird as the mail client as already has configured for few more email accounts?

  41. Vibhakar Bhushan says:

    I have Outlook2007 installed and have 4 PST files, which I would like to import to Thunderbird. In Thunderbird, under Import function, I get only Outlook Express as the option. No mention of Outllok2007. What should I do?

  42. Larry P. says:

    Seeking informed advice …….. I have been running Thunderbird since I got my laptop 18 months ago. I recently bought/installed Office 2010 and have just now been trying Outlook 2010 for past two weeks for some of those Outlook features that I was familiar with. Both have Pros and Cons. Not sure which is the smarter choice and whether the migration is worth the effort. I am also looking into which is best if I want to find a way to keep my email system calendar in sync with my new iPhone 4S just acquired 2 days ago. Any input is appreciated… Thanks. Larry P.

  43. Sandmich says:

    Thanks for the info. I was looking for a reliable method to get ’eml’ files into Exchange and using Outlook Express as the intermediary does the trick!

  44. sam says:

    I setup Thunderbird it not ask me if I want to import my Outlook email

  1. 3/19/2008

    […] From Outlook to Thunderbird and Back Again. […]

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