I want all users to authenticate before sending email. I am using exchange 2013. so how will i configure authentication for SMTP on my exchange 2013 

Hello

tip: if CAS receive directly receive email from internet then create new receive connector and set auth only and add internal ip to scope

There is nothing to configure - Exchange 2013 is ready to do that out of the box.

The Client Receive Connector is the connector designed for this job. You will need to configure the POP/IMAP client to authenticate on sending. Do not use the option for the same credentials as inbound, you need to specifically set the credentials.

Although that is presuming that you are using POP3/IMAP. If you are using Outlook Anywhere/EWS/ActiveSync then it isn't possible to have authentication before sending. I would also question why you have Exchange if you are going to use POP3.

Simon.

Dear Bladfaust;

Can you please explain what you gain from this, if you need to force the security in your mail system you can using Domain security by configuring a mutual TLS.

Hi,

Hope below article will help you

http://exchangeserverpro.com/exchange-2013-configure-smtp-relay-connector/

Hi,

In Exchange 2013, the default Received connector named "Client Frontend <Server name>" listens for authenticated SMTP client submissions on port 587 on the Client Access server.

If you are sending message to the internet from Exchange server, all sending and receiving are on SMTP protocol. For more information about this, please refer to:

https://technet.microsoft.com/en-us/library/bb331973(v=exchg.150).aspx

Regards,