Windows Live Mail is the successor to Outlook Express. It allows adding both a chat button and a chat link for emails to the email signature.
If you send emails in HTML format, you can add there a chat button for emails or a direct link to your Visitor Live Chat Messenger. The chat button in this case will be displayed as a chat icon and a direct link will appear as a URL
To insert a chat button to your signature, please do the following: >>>