Cannot Send or Receive Emails?

I am suddenly unable to Send or Receive emails. Was OK yesterday morning, but by evening I could not? What happened and easy way to FIX this?

Why can't I see any response happening? I need help!

You didn't see any response for a few reasons, one being that you only waited 3 minutes before asking about it. Another being that this forum is volunteer users helping other users, and they have lives to lead and may be busy. Another being, you didn't provide much information to go on. So, lets start again:

- What version of Thunderbird?

- What is your operating system?

- Who is your email provider?

- Is this an IMAP account or POP3?

- What error messages do you see? Please quote them precisely and in full. Screen shots would suffice.