Connecting to an SMTP Server

You ll start by looking at the simple snippet of code in Listing 24-1 to see how you can establish a connection to an SMTP server.

Listing 24.1: Initializing a Connection to an SMTP Server

 1  #include <atlsmtpconnection.h>  2  #include <atlmime.h>  3  4  CoInitialize(NULL);  5  6  CSMTPConnection smtpConnection;  7  if (!smtpConnection.Connect("localhost"))  8  {  9    printf("Could not connect to SMTP server!\n");  10 } 

 

Listing 24-1 is obviously very short, but we ll take a quick line-by-line look at it:

• Lines 1 and 2: All of the public support for SMTP and MIME in ATL Server is implemented in the atlsmtpconnection.h and atlmime.h header files. These classes make use of some of the constants and utility functions defined in atlsmtputil.h.

• Line 4: ATL Server uses the MLang services to help with the conversion between the local character set and Unicode. These services are exposed via COM interfaces, so COM must be initialized before ATL Server can query for these services. In general, MLang provides services for writing internationalized software for the Internet. We recommend looking up documentation in MSDN for the IMultiLanguage interface as a good start for learning about MLang.

• Line 7: The name of the SMTP server you re connecting to will depend on your network setup. You can optionally specify a timeout for the connection; by default, the timeout is 10 seconds.

You ll spend this chapter looking at the major classes in ATL Server that support SMTP and MIME. You ll also take a look at how to implement some of the more common scenarios that SMTP and MIME are used for. In the next section you ll examine the CSMTPConnection class.