lets back up a bit and clarify some thing. it will make it easier in the future if not now.

Att/Yahoo is a mail provider. Their mail is available normally through a web portal and can also be collected by a mail client such as Thunderbird or Evolution or Outlook.

Thunderbird is a mail client. If connects to the server of mail providers and collects the mail from them.

Therefore you can not "import" mail or folders from the provider.

You can create the email account in Thunderbird as an IMAP account and it will download all of the folders associated with the account and keep them in sync with the Yahoo server. Just remember the synchronized part.

ATT say they have IMAP support see http://www.att.com/esupport/article.jsp?sid=33462&cv=820#fbid=1un4iZGqwZ9

Thanks for answering but I am still confused. I have my accounts set up in Thunderbird for several years but they always default to POP3 accounts. So I have my ISP as ATT and when I set up a mail account in Thunderbird it automatically chooses POP3. I just tried to set up another new account as IMAP but it failed. From your email, I thought I should set up an IMAP account using my AT&T login and password, was I wrong? Thanks again, Bill

Thunderbird's database of account setting only included POP for ATT, but you can override that by clicking the manual config button.

In the link I provided are these settings IMAP imap.mail.att.net 993 Yes smtp.mail.att.net 465 Yes

Which you use to set the manual configuration.

Matt, I was wrong. I apologize. I failed to type the IMAP settings correctly when I tried to build the IMAP account in Thunderbird.

I will try this on my cousins computer as soon as I can.

Thanks again for your help. Bill