To add this button to your own talk page, you can use {{User new message large}}. It can easily be modified: Colorful examples are provided on the "Template:User new message large" page.
Please note that you are currently not logged in.
This is not a general problem – you can leave a message anyway, but your IP address might change during the discussion, and I might end up talking to a wall. Creating an account does not require an e-mail address; all you need is a password and a name. You are not required to do this, but please consider creating an account before starting long-term interactions with other users. Thank you very much in advance. 
