To understand your situation, please define the three accounts on whether IMAP or POP and at least provide sample email addresses so we can see if it's three unique accounts. From what you posted, I am unclear on whether this is one gmail account that is setup multiple times or something else. Thank you. Are all of them Gmail accounts?

Hi David. In Thunderbird I have three accounts set up. Two of them are not gmail accounts and one is my gmail account. All are pop3. The two accounts that are not gmail download their messages to a global inbox folder. The gmail account has its own inbox folder. I have had this type of set up for a couple of years with no issues. What I want is that only the downloaded gmail goes to the gmail/inbox folder and the other two emails download into the local/inbox folder. I had this set up working for a couple of years but recently had to set up a new laptop. Now things don't work like they used to.

If one of the non-gmail accounts is also appearing in the gmail inbox, my first thought would be to check the online gmail account to see if it is capturing mail from another account, which is a gmail option. My second thought would be to see if the non-gmail account is forwarding to the gmail account. My third thought is to go online to the gmail account itself to see if the non-gmail messages appear there. That research may explain the issue. I am not familiar with the POP global inbox, but searching the thunderbird settings seems the nore unlikely to have captured one account and displayed it in a separate account on its own. (But I've been wrong before.)

So let me clarify my gmail account. My gmail account is set to also retrieve all emails sent to my other accounts. I did this so that when my windows machine craps, I don't lose all my emails. Once again, this is the way I've had it set up for a couple of years and didn't experience problems. Originally gmail would capture all emails but the thunderbird gmail account would only download those emails addressed to the gmail account. Now the thunderbird gmail account is downloading all of retrieved emails. I still don't know if I am being clear. My guess is that this is probably a gmail issue and not the thunderbird issue but I can't figure it out. Maybe it won't work this way anymore but it used to.