Perhaps your first mistake is setting the download to 10 minutes. Hotmail for example refuses connection attempts if they are less that 15 minutes apart for POP accounts..

That is Thunderbird's default - I didn't change it. Yesterday someone sent an email @4 PM. I opened Thunderbird several hours later and by chance sent the same person an email, not realizing he had sent me one. When I punched "get new messages" i found his email. So it doesn't check when opened or automatically; if I am actively using it, it seems to accept and show new emails. Thanks.

What mail provider are you using? There is at least one US based ISP that has defective mail server software.

Right click the account in the folder pane and select settings. What is the server type shown? Is check for new messages at startup selected? If the account is POP,

• is automatically fetch new messages selected?
• click advanced. IS the include this server when getting new mail selected?

My provider is Comcast, the server type is POP, "check for new messages" IS checked, "automatically get new messages" is checked, and under "advanced" the "include this server" is grayed out since I only have one server. Thanks, Lee.