It is related to test forum only. We have disabled emailing features there to avoid any kind of emailing spam - don't forget they are pure public forums. So you test this add-on by steps until actually send the message (recently we have updated it so at least the posting form step appears, please check now - and thanks for this report...)

I have tried and everything works nice.

Many thanks for this addon.
It works when I sign in as a member, but not as guest.
I would like to allow guests to send emails to members, can this be done?

The Contact/"Click to Send a message by Email" link brings a blank page when I am not signed in.
I did not put checking on user ID as mentioned above.

My board is for registered members only. I have added a simple security access code (not captcha) for the email form to prevent spams.

Thank you for any assistance.

You can try to edit this addon script and comment/remove: if ($user_id>0) ...

Oh that is so brilliant. Thank you tom322 for the quick response.

Just strikes me that the Report link ({$reportLink} variable) appears even in closed topics in posts. How can I stop this?

A closed topic i can determine, for example via parseTopic and if($GLOBALS['cols'][5]==1) ... but here I have to work well with the functional parseMessage ... and just i have no idea for the right code :-/

You may refer to $GLOBALS['topicData'][1] indeed.
I.e.
In the case of this add-on, you may extend this (default) code to:

Thank you Paul, it works exactly as it should.