when do (gnatsweb or cmds) send email?

[doug . mildram]

Hi! I upgraded my site (gnats 3.2) to 4.0-beta1
THANK YOU SO MUCH!! Finally, we can add "classes".
AND!!! the new gnatsweb is SO much better ...
    and faster (thanks to the improved index, no doubt)

I/we do NOT use "incoming email" as "input",
 but we do use gnatsweb AND unix commands (e.g. edit-pr).

My general? question is: 

  ---when does "the system" (gnatsweb, or edit-pr,
                        2 different answers I imagine?)
        send email?  

My belief so far is that:
Not ALL edits/changes send email, though some do.
(adding text to gnatsweb description doesnt seem to...
  changing responsible person DOES seem to....)

I dont THINK that gnatsd itself sends any email.      

I'm studying the gnatsweb code, but it's going slowly,
and that's probably only half the picture anyways.
Is there any "local configurable control" over this?
================================================================
Doug Mildram  Mindspeed Technologies 
address@hidden     8 Technology Drive             
Systems Admin.                 Westborough, MA  01581