Thunderbird: Sending of the message failed.
Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) smtp.gmail.com failed. The server may be unavailable or is refus… (read more)
Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) smtp.gmail.com failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again.
What can I do?