User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US) AppleWebKit/533.2 (KHTML, like Gecko) Chrome/5.0.342.9 Safari/533.2 Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1.9) Gecko/20100317 Lightning/1.0b1 Thunderbird/3.0.4 If you have multiple accounts, Thunderbird only download new mails from account nr 1. If you manually click "get mail" for account nr 2 then you get the mail that's on the server. But i you are running Thunderbird a couple of minutes the you get the mail from account n2, probably because the "Check for new mails every X minutes" Reproducible: Always Steps to Reproduce: 1.Start Thunderbird. 2.Thunderbird starts downloading mail from account nr 1 but not nr 2. 3.Click manually on "get mail" for account nr 2 and then you get all the mail on account nr 2 if there are any new mail on the server. Expected Results: When you have multiple accounts in the "Account manager" and you have checked "Check new messages at startup" on respective account you assume that Thunderbird checks all the accounts when it starts up. Using 2 different pop3 mail accounts with Google mail, so the account settings are almost the same, except