burnout426: I have gone to the link you provided and that extension is what I would like, except that once installed it doesn't work. It starts to open a new tab, like the "Send this Page by Email" Chrome extension does, but does not open a message window in my default email client. Sigh
Close Opera. In the control panel, under "Default Programs", make sure your mail client has all its defaults. But, specifically make sure it's handling the "mailto" protocol. If your mail client already has all its defaults, set it to something else and then back to your mail client. Then, start Opera and try again.
If that doesn't work, we can investigate the registry to see if the proper command for your mail client is listed under the "mailto" protocol.