Importing from Eudora - Thunderbird
From MozillaZine Knowledge Base
Note: Importing from Outlook and Eudora in the built-in import wizard was disabled in version 38 as they broke. Eudora import was permanently removed in version 48. You can work around this by using an older version of Thunderbird. Version 17.0.9 is probably your best bet as version 24.* and 31.* sometimes crash when importing. See Go back to an old version of Thunderbird for links to those setup programs.
Thunderbird data import is not always successful; there are many variables such that you may get bad messages, crashes, etc. So it is recommended that you backup Thunderbird and Eudora data prior to doing imports, so that if a problem does occur then you have the data needed to troubleshoot the issue, and rerun the process at a future date. Keep your original data for an extended period of time so that if a problem is found then you have the data needed to reproduce the problem such that someone can fix it.
To migrate from Eudora to Thunderbird:
The two programs store attachments differently: Eudora detaches them from the e-mail and stores them separately as files, usually in a folder named "Attachments" or "Attach". Thunderbird keeps the attachment together with the e-mail.
When importing from Eudora, Thunderbird attempts to join the attachment back to the e-mail it came with. This can take quite a long time if there are a large number of attachments. Also, because they include the attachments, Thunderbird's mailbox files are larger than Eudora's, though that is usually harmless.
If you want to prevent Thunderbird from re-attaching the attachments, you can try to move the folder containing Eudora's attachments to a place where Thunderbird will not find it. IMPORTANT: Do not delete Eudora's attachments folder or you will lose all your attachments. Also, please note that this solution is untested; use it at your own risk.
Importing Eudora Mail with Eudora Rescue
The following issue is fixed in Thunderbird v3 by bug 368347. Note, Eudora Rescue has not been updated since 2005.
Thunderbird 1.0 and onwards has improved importing of the Eudora e-mail, but it still cannot maintain the messages' status. Until this is fixed, perhaps the best method of conversion is with the use of the Eudora Rescue utility by Qwerky. See the README for instructions for using Eudora Rescue. After you have used Eudora Rescue, you can import the mbox into Thunderbird or Mozilla Suite using the ImportExportTools extension.
In 2012 the author of this note attempted to import about 2 GB of Eudora e-mail (mail only, no address book, etc.) using Thunderbird 11 (which was current at the time). The import hung on a specific mailbox, but could be cancelled leading to a crash of Thunderbird. In any case, the import was of poor quality as sent messages were imported as unread and didn't have correct dates, since Eudora hadn't stored the dates. A much better result was obtained using "Eudora Rescue" (with the -z option) and then importing with Thunderbird 1.5, which was current in 2006, so the same vintage as "Eudora Rescue". Modern versions of Thunderbird will fail to import the data pre-processed with "Eudora Recue".
There is little chance that Mozilla will ever improve the Eudora import. According to the author's experience pre-processing the mail with "Eudora Rescue" and then using a very old version of Thunderbird is still the best way.
Importing Eudora Mail with Eudora Mailbox Cleaner
Although it only runs on Mac OS X, you can use Eudora Mailbox Cleaner to import your Eudora messages from either the Mac or the Windows version of Eudora instead of using the import function built into Thunderbird. Eudora Mailbox Cleaner should be able to
Windows users who have had no luck with Windows native tools, might experience better results transferring to a Mac, converting and then transferring it back.
The easiest solution is to use the automated import of the address books. However, you could also
This will not import the mailing lists , which are stored separately.
Outgoing Attachments Fixer
If Thunderbird didn't migrate attachments for sent messages use the Outgoing Attachments Fixer program to modify the *.mbx files and then import them again using the Tools menu. The program is run from a console window. For example:
Thunderbird 2 doesn't support importing filters so there is no support for importing .pce files. Thunderbird 3.0 does support importing filters but its not clear yet exactly what functionality it provides