The Email will come from the 'Email' column on SETUP_SITE_MANAGE. You either need to be using your own email sending, or have this email verified as per Email Sending  
  Document Numeric Optional. The Id of the Document if you have a custom lost password document. This document needs to have the tags [LOGON], and [PASSWORD]. You can also have your own tags to pass additional information. These fields must start with TEMPLATE_.  For example, you could have [TEMPLATE_PARAMETER1], and then pass TEMPLATE_PARAMETER1=fred
  ExpirePassword Text (1) Y / N [default]. If 'Y' the password will be set to have expired yesterday
  Logon Text Mandatory. User's Logon
  MySiteOnly Text Y/N. If Y, it will only email if the Logon is in your site
  NoSystemTemplate Text Y/N. If Y, your standard email template will not be applied to the email
  template_xyz Text You can also pass additional fields to be merged into your template document. For example, in your document you could have '[template_xyz]'. Then if you pass 'tamplate_xyz=abc', then the value of abc will be subsituted in. As a note, you need the square brackets ('[', ']') around the field, and the field must start with 'template_'.