Thread: Making an Email Server

This is a long way from "Hello World", so be sure to plan it out. You will want to understand RFC 822 and, should you decide to support MIME, RFC 2045 (and 2046 as well, I believe). These documents will help you understand how email messages and attachments are formatted.

You will also need to understand TCP sockets as well as SMTP to communicate with other email servers, so that your properly formatted email messages can actually get somewhere. I'm sure a Google search will turn up the specs for SMTP and some TCP socket programming tips.

After you have read and understood the requirements of the RFCs and other documents, grab a pen and paper. Sit down in your favorite chair with a caffinated beverage of choice and plan out the overall logic. Then you can code, debug, and test :)

You may also find it worth your time to download an opensource SMTP server and review the code.

Good luck.

http://sourceforge.net/

Originally posted by Nutshell
What are some sites you would recommend which has open source programs?

Freshmeat is another excellent open source site.

Knowing TCP socket programming will be a big help to you. :) You may want to use gethostbyname() to fill your hostent structure. SMTP traditionally listens on port 25.

Code:

#include <netdb.h>

struct hostent *hostaddr;
extern int h_errno;

hostaddr = gethostbyname( "yahoo.com" );
if ( !hostaddr )
{
  /* gethostbyname sets h_errno with the error number */
}