I'm trying to setup an existing email account, but the problem is that every time I set this up on a new machine, thunderbird says the login password is incorrect, even though it is definitely correct.
Using Thunderbird on Linux Desktop, with IMAP; all OK
Hello: I believe you have one or more configuration settings incorrect. I have been using Mozilla Thunderbird (a 2.x version, which is the latest available for the OS I use) for a long time, on CentOS 5.6 (32 bit).
I use IMAP and backup my email to my Desktop PC, just in case something goes awry on the server.
Before you try to configure Thunderbird again, see if you can log into your email, on the web, with SquirrelMail or something, and see if you can send and receive one or two test emails.
If that works OK, then check and double check the settings you have been trying with Thunderbird. GL
Hello : If the issue is only with thunderbird and that your emails are working fine on webmail , then there is a chance that the password is corrupted and you can have it corrected by having it once again reset from the Cpanel of the domain under email management and using the new password on thunderbird.