Hi Ashak, your post got filed under Firefox... Is the problem with the Thunderbird email software? If so, a moderator can move your question.

Meanwhile, is there a specific error message explaining why the message can't be sent?

Do you have instructions from your email service on the settings to use? If you weren't able to find all the necessary settings in Thunderbird on the first try, that could be the issue.

Hi, yes this an issue with thunderbird e mail !