move the whole profile. Thunderbird does not move a bit here and a bit there easily or painlessly. There is a reason this support article does not recommend moving just the address book or just a pop account. https://support.mozilla.org/en-US/kb/moving-thunderbird-data-to-a-new-computer

Thanks Matt, I understand your response. And I think you are telling me that the old profile, with the two Imap data, are substitute-able for the new profile that was modified by the adding of the two same Imap accounts. OK, I get it. Thanks

Blunt, but to the point. It is only because your already added accounts are imap and this did not turn into a mess. I particularly like the youtube video on the how to article.

Thunderbird keeps information in folders that are allocated by account number and type. taking bits is not easy, as the account number is basically a random number as it is issue based on the number of tries to add the account you have, plus the number of accounts on that mail server. So if you are with yahoo. You could have an account folder of yahoo to yahoo99 if you have been adding and removing accounts. That does not translate well to a new profile with different numbers for accounts. Hence moving everything. that way you also get your add-ons calendars and contacts and everything just fits.