I updated my Ubuntu installation from 22.04 to 24.04. Unfortunally, thunderbird could not import my old profile. I did not create a backup of my profile and tried to create a new account for one of my mailing addresses in order to access my new mails. While I was able to receive new mails, I unfortunally could not read my already downloaded mails stored locally on my computer. I realized that I could restore other accounts for other mailing addresses by importing my profile folder, but for the first mailing address the mails stored locally are still missing. I expect they are still saved in the folder due the huge size of the folder (>7GB).

Does somebody has an idea how I could access the mails in my local profile folder.