Hello there ander s We have read your message. We try to help you. Before we troubleshoot this issue, can I ask you a few questions to gain more insight into this situation? The most important thing in this kind of situation is to see from both sides whether you know Smtp settings properly and correctly at the moment. With regard to receiving and sending, but also with the receiving party of these actions that you perform. https://support.mozilla.org/en-US/kb/cannot-send-messages Greetings Firefox volunteer.