The worst

It is the worst! I've sent an e-mail to client, or sent DM for them ever since but sent e-mail was not able to return to me. That problem caused during setting up the Thunderbird which is e-mail application. What the  hell am I doing!! I couldn't receive clients reply if they send me it.I am waiting for client reply in my room a long time....
Anyway, it was already solved. So I have to send an e-mail again a lots for client from now. Please wish me...