
Synchronisation
I have two computers and Thunderbird is installed on both, both computers have the same Gmail account, if I use the first computer, I get the current mail from gmail. After that, I turn on the second computer and the messages that were downloaded to the first computer do not appear on my Thunderbird. In my settings, it is stated: "leave all messages on the server." On both computers, there are other accounts. They are not Gmail and there I receive the same messages on both computers, nothing is missed. I tried to use articles about synchronizing messages in Gmail, but they contain instructions and illustrations that I do not see in my settings, that is, I do not have a synchronization section in my settings at all.
Todas as respostas (2)
From your words, I infer that you are using POP accounts, which do NOT synchronize. If synchronization is a priority, I suggest switching to IMAP. If you still want POP, I suggest careful review of al settings on both PCs and also check online to verify that messages are there that are not appearing on the second PC. Something here is amiss, and I'm not sure where to start first.
If you access a gmail POP account on multiple desktop PCs through apps like TB, you must enable recent mode by appending recent: to the User Name. See the first section of this article.
Consider configuring the account as IMAP on all devices to synchronize mail.