Suddenly this morning, I can't send an email through Thunderbird, but I can through my email service provider's platform. No settings have been changed and I have the most up to date version. I get this message: "Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) (my account) failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again." I am not at all tech savvy with this type of thing, so I need step by step, easy instructions, please. Thank you!