gMailto is a handy extension for Opera that can make Gmail your default mail client in Opera. It will open a Compose window in Gmail when you click a mailto: link, while the extension is running.
To install gMailto, go to this Opera extension page. After installation, restart your Opera. Now onwards all email links you click will be rewritten so that they redirect you to a Gmail-compose window. All attributes, such as recipient, copies and subject, will be forwarded to the composer. gMailto extension will be handy if you prefer Gmail rather than your desktop mail client for composing messages in Opera.
