hi all I was using with no prob outlook express until 2 days ago; nothing is changed in my config I started to have problems only in sending messages. I'm using win xp 32bit sp3. The company that build our website and provide email server told us to try to use Thunderbird. So I do and it looks great. I like. But I have the same problem. Mail arrives but error in sending. I wrote again to our technicians and they wrote this (I used translate sorry for mistakes): "Good morning, after a thorough investigation we came to the following diagnosis. Regarding the SMTP / IMAP connection from Windows XP with clients such as Outlook, we inform you that the cause is in the configuration standard for SSH (ciphers) certificates that the various control panels (Plesk / Cpanel) have adopted to correct the security breach on SSL / TLS protocol. Configuration is not supported by obsolete operating systems such as Microsoft Windows XP, which has been terminated by Microsoft on April 8, 2014 (https://www.microsoft.com/en-us/windowsforbusiness/end-of-xp-support )." Is this true? do I have other chances istead to update OS? Update OS is a problem because with Win7 and higher our management software will not work. Many thanks in advance for support. Best regards David - Italy