To modify the subject line find the line 95 below: $Subject = "In reference to $Address";  then modify to suit.

There are 2 tags available to use in your listing template

1. {addon_contactagent_agent} - a link to a popup window
2. {addon_contactagent_agent_embed} - embed in listing page

The addon also supports the image verification using captcha with newer versions of Open-Realty
  if ($config["use_email_image_verification"] == 1 )

This addon is not encoded and is available for immediate download.