System:
Microsoft-IIS/5.1
AspNet-Version 2.0.50727
YAF version:YAF-v1.9.3-FINAL

I have wrote some code to automatically send a private message via URL such as:
http://localhost/DNN_490_Test/desktopmodules/yetanotherforumdotnet/Default.aspx?&g=pmessage&u=13

After figuring out what this does by hand I recreated the Post and the Request headers as described below. The response is suppose to send back a Location header which is http://localhost/DNN_490_Test/desktopmodules/yetanotherforumdotnet/Default.aspx?g=cp_pm&v=out
instead this always responds back and takes me to the Private Message compose page (e.g., g=pmessage&u=13).

Any ideas? Thanks

Post:
__EVENTTARGET=
__EVENTARGUMENT
__VIEWSTATE=/wEPDwUKL ...
forum$ctl01$Subject=Mike+sent+you+a+message
forum$ctl01$edit=this+is+test
forum$ctl01$Save=Post

Request Headers:
(0) "Content-Type" String: "multipart/form-data"
(1) "Referer" String:
http://localhost/DNN_490_Test/desktopmodules/yetanotherforumdotnet/Default.aspx?&g=pmessage&u=12
(2) "Host" String: localhost
(3) "Cookie" String: various cookies that are needed including .ASPXANONYMOUS, etc.
(4) "Content-Length" String
(6) "Connection" String: Keep-Alive

Not a problem with YAF: moved to integration.

I was way off base on the approach and see that I basically need it to go through the path of pmessage.ascx.cs.Save_Click in order to work.

You're still pretty off... but getting closer. Don't ask for more help from me, though. You need to figure out how to do it yourself... that's what coding is about.