I am using Ubuntu 12.04 LTS and Thunderbird 14 I have configured correctly all accounts using common Local folders I send and receive correctly emails. Suddenly, usually 4-5 hours after I switch the pc on, I can not send email but receive only. Other information is that it is a dual boot pc with Vista and both OS are using same profile folder.
The problem I found out is generated every time
dmesg.log is updated. Solution is to reset wireless connection. It is generally not only Thunderbird but sending out network connection problem.