I am writing an small application which uses sockets to send mail.
When i specify the outgoing mail server(ex. smtp.sify.com) , i am able
to send mails to only sify accounts(ex. a...@sify.com). If i try to
send mails to non sify accounts(ex. mur...@yahoo.com) it gives error
message(Relaying Access Denied) saying that it requires authentication
for relaying. I sopke to my friends they told that if i specify
username and password that we give in outlook express for autheticating

the outgoing mail server then it will work.

I tried the same behvaiour from outlook, if i specify username and
password then sify server does the relaying otherwise it fails.

I don't what request i have to send to mail server through my
application using socket to the autheticate or authetication is a part
of MIME header , if so what is the header. Anyone knows how to send a
request please share it.