Does SmtpClient class represent POP3 client or…?

Question

1. I assume that web controls (such as the PasswordRecovery control) use SmtpClient to send email messages. If so, does SmtpClient represent a POP3 client or does SmtpClient forward email message to POP3 client?

2. Do attributes specified inside <smtp> element in web.config map to SmtpClient class?

   <system.net>
     <mailSettings>
       <smtp deliveryMethod="Network" ...></smtp>
     </mailSettings>   
   </system.net>
   

3. One of the possible values for the attribute deliveryMethod is Network, which tells that email should be sent through the network to an SMTP server. In other words, this value tells to send email to SMTP server using SMTP protocol?!

4. For the PasswordRecovery control to be able to send email messages, we need to set basic properties in <MailDefinition> subelement of the PasswordRecovery control. Thus I assume MailDefinition is used by controls to create an email message?!

thanx

Answer 1

SmtpClient speaks SMTP!

Email servers receive via SMTP and you retrieve data via POP3 or other protocol.

Two clients will NEVER talk to each other. One client will send to the server. The message will be forwarded from one server to another until it reaches the one where the recipient's email account is registered. Finally the client will connect to that server and retrieve the e-mail.

Answer 2

The SmtpClient class represents (as the name suggests) an smtp client, not a POP3 client. The SmtpClient class uses the smtp configuration section to pick up default values for its operation.

Your interpretation of the NetworkDelivery value is correct. The other delivery methods make use of pickup directories (which actually is a rather nice approach; it disconnects the code from needing the SMTP server to be up and running when the mail message is posted).

For further details on the SmtpClient class, I would suggest to dive into the documentation of it.

And yes, the MailDefinition is used internally in the PasswordRecovery control to create the mail message.