Outlook no longer supports POP3 so I have installed Thunderbird, with help from my provider, Zen. A can receive messages but cannot send them. Zen cannot help and say it's probably due to a default server name and I need your help. These are3 the messages I receive when trying to send an email: Sending of the message failed. The message could not be sent because connecting to Outgoing server (SMTP) mailhost.zen.co.uk failed. The server may be unavailable or is refusing SMTP connections. Please verify that your Outgoing server (SMTP) settings are correct and try again. Set up: Description: zen81982 Server Name: mailhost.zen.co.uk Port: 587 User Name: zen81982@zen.co.uk Authentication method: Normal password Connection Security: SSL/TLS