If the second account is POP, I hope you have not begun using it yet, as that immediately places the two versions of the account out of sync. When moving POP accounts, it is important to stop all downloads during the transition period to ensure the account stays in sync. Then, create account on new PC and then, in Windows File Explorer, copy the Mail/POPaccount from old profile to new profile, exactly overlaying the same folders that were created when account was set up.

The first account is IMAP and the second is POP, on both the old and new computer. Do I use the on-line instructions to move the Thunderbird files from the old to the new computer? Just asking to be sure as I don't want to lose any emails. thanks

Not sure what you mean by online instructions. Are you using the POP account on new computer prior to moving message folders from old computer? I need that to ensure I give proper steps.

David, Yes I'm using POP on the new computer and POP on the old computer. How do I move the folders from the old computer to the new computer. thanks

Ok. It is much easier if you convert first, but this can be fixed, - during this process, do not run TB on old PC - exit TB on new PC if running - copy the profile to a safe place from c:\users\<yourid>\appdata\roaming\thunderbird (just being safe) - on new PC, start TB and remove password to prevent message retrieval - using the importexport utility, extract all messages from inbox and sent folder to EML format in separate external folders. We will want them later - exit TB on new PC - in windows file explorer, on old PC, copy the Mail\POPaccount inbox and sent folders to overlay/replace the same folders on new PC - start TB on new PC and use import/export utility to import the EML files to inbox and to sent folder. This should get the folders in sync - enter password and continue normally

David, I'm confused, your instructions seem to overwrite the profile from my old computer onto my new computer. I don't think I was clear with my problem. On my new computer I have email account1, running IMAP, up and running. This was moved using the instructions on the Mozilla website. I have a 2nd old computer running email account2, running pop. Email account1 and email account2 are different email accounts.

If I move the profile from email account2 to the directory with email account1 won't that overwrite that account?

I don't want to merge the accounts into one account but keep the accounts separate.

Do I need to change the POP account into a IMAP account? if so how.

Let me know if you have questions. thanks

Ok, I'll try to rephrase my suggestions, since I did not want you moving the entire profile. The challenge is that you have POP on both, meaning the message folders are out of sync. You have some options: 1 - merge the messages on old PC with messages on new PC. That's a number of steps but doable. 2 - copy the messages from old PC to local folder on new PC. That retains them, but you would have messages in two folders, one in local folders and one in IMAP. 3 - you could convert the POP account to IMAP, but that leaves you with messages on old pc and on new pC and those would need to be put in local folders, leaving you with two message folders locally, plus the IMAP folder.

Tell me which approach you want and I'll try to give the necessary steps.

David, I want to have two email accounts in Thunderbird on my new computer, with separate inboxes and files for each. So I want to use option 2, copy the email/folder from the old computer to the new computer. Also the existing email account on the new computer is using IMAP while the email account on the old computer is using POP.

thank you

Ok, all three options retain having separate inboxes and separate files. Here are steps for number 2: - with Thunderbird NOT running on either PC, - locate the message folders on old PC. that would be in profile in Mail\<account> (e.g., INBOX, INBOX.msf) - copy to NEW pc in Mail\Local Folders folder - if there are other folders on old PC, possibly in Local Folders, use same technique to copy them also. - start Thunderbird and the messages should appear in Local Folders.

Dave, Not all of my mail folders moved over, I have about half of the folder on my new computer. What can I do to get the remaining folders onto my new computer? thanks

Are you using windows file explorer for the moves? These should be just file copies from one profile to another. Do you see the folders in the new profile with same size as in old profile?