What is the use of pop3?

Dear Friends,
What is the use of the pop3 classes.
If anybody could give some example for pop3 classes.
And also I need to know how can i send the email using the smtp.
For me it is working,while send and receive the mail only witin the
intranet.
but it is not going out side ,for exampl,yahoo and rediffmail.
Please any body tell me.

by
vellingiri.

Vellingiri A. wrote:

     What is the use of the pop3 classes.

If anybody could give some example for pop3 classes.

What does El Goog say about POP3, the Post Office Protocol v3?

And also I need to know how can i send the email using the smtp.
For me it is working,while send and receive the mail only witin the
intranet.

but it is not going out side ,for exampl,yahoo and rediffmail.
Please any body tell me.

They are probably secure, and you probably need to add an encrypting
layer.
To send to Yahoo, you must hit an SMTP server that trusts you. You can’t
use
simple TCP/IP techniques to hit Yahoo’s mail web pages. You can use
complex
ones, but that’s sloppy and hard to code. Yahoo cannot allow you to use
SMTP, because you could be a spammer, and we have all received spam with
the
yahoo.com domain.

Your best bet is your immediate upstream ISP, because they can trust
your
computer at the hardware level, and allow you to SMTP out of it. So this
will require asking your ISP what they tell civilians to type into their
mail configuration dialog boxes, and then translate this into raw TCP/IP
settings. There will be at least a domain name, port number, user name,
and
login. And there had better be an encryption protocol, too, unless you
completely trust your password going over the open internet in
cleartext!