The complexity depends on your situation. The last version of Eudora came out in 2007 and a lot has happened since then. If your accounts are IMAP, there is one set of steps to switch, and if POP, a very different set. Tell us more.

Hi David,

Thanks for the tag.

The accounts are POP.

Marc

This URL gives the basics: https://support.mozilla.org/en-US/kb/switching-thunderbird#w_importing-from-outlook-and-eudora

The steps are to install an old version of thunderbird that has the eudora import feature. Then, after doing the conversion, click help>about and click to upgrade. That will upgrade but to a later, but still old version. To migrate up to current version, there are multiple steps, as Thunderbird did automatic adjustments on key upgrades. That is explained in detail on this URL: https://support.mozilla.org/en-US/kb/upgrading-older-version-thunderbird.

In going through the updates, be sure to do backups after each one. The steps for that are:

1. exit thunderbird
2. copy the profile at c:\users\<yourid>\appdata\roaming\thunderbird to a safe place (should you need to restore, copy the backed-up thunderbird folder to c:\users\<yourid>\appdata\roaming to overlay the prior version.)

If you don't mind some manual adjustments, you could, of course, upgrade directly to the current version. That can work, but it needs tweaking.

That’s very helpful, Dav id.

Thank you.

You're very welcome.