SMTP MFC Classes

The classes presented in this article allow your application to send e-mail using the SMTP protocol. They are part of a library I developed for a series of projects that includes a POP3 class, an IMAP class, and a PostOffice class that manages all e-mail activity and provides a storage mechanism (like Outlook's folders).

This implementation of the SMTP protocol differs from the other on this site (which is very good, and easier to understand than mine) in that I deal with messages as discreet entities that are passed around to objects that do something with them (like send them using SMTP). Additionally, I hide all protocol "ping-ponging", prefering to do a single SendMessage() call as opposed to a sequence of "MAIL From:", "RCPT To:", and "DATA" function calls.

Additionally, this code shows how to properly construct a header and cook a message body.

There are two classes in this package, and I'll describe briefly how they are used:

CMessage

This class encapsulates an e-mail message. It differentiates between the header and the body, and builds standard header lines such as From, To, Date, and X-Mailer. In addition, it supports "friendly" names in the From and To fields. Altogether, this class allows your application to send "cooked" messages to the server instead of raw DATA commands.

I have a derivative of CMessage that handles file attachments, which I may or may not post later (depending on whether or not I post them, which I may or may not, depending).

CSMTP

This class prepares a CMessage and handles all negotiation with the server, including getting the local host name for the HELO command, prepping the message header and ensuring that the body is fit to send (such as the case where user types a single period on a line-- it's part of the message body, but if not handled correctly, SMTP will treat it as a end-of-data marker and all remaining body text will be lost). I'm sure there are some monkey wrenches that could be thrown into it that would clobber some mail readers, and if you find any I will un-ignore you.

In short, its a relatively robust package that can be used as the basis for real applications with a little tweaking.

Sending Mail

Sending a message is easy:

void CMyView::OnClickSendButton()
{
	CMessage msg;
	CSMTP smtp( "mymailserver.com" ); // You can set server/port later, too.

	// Populate the message
	// Note the friendly names, and that recipients can be added in bulk
	// or individually.
	msg.m_sFrom = "Ultramegahunk<clyburnw@enmu.edu>";
	msg.AddMultipleRecipients( "Pookie<pookie@foo.com>;Snuggle Bumpkin<snuggles@chakka_khan.com>");
	// Oops, forgot one
	msg.AddRecipient( "elvis@graceland.com", "You're Dead" );
	msg.m_sSubject = "Ouch";
	msg.m_sBody = "Ow, god, mom, the dog he bited me.";

	// Send the message
	// You can connect once, and issue multiple SendMessage()
	// calls before disconnecting-- all messages in an "inbox",
	// for instance.
	smtp.Connect();
	smtp.SendMessage( &msg );
	smtp.Disconnect();
}	

Using the Package

I've included Component-Gallery-ready files in the ZIP that can simply be added to your project. You might want to make a folder for them in your SharedIDE directory, and toss their butts in there. The files are "Mail Message.ogx" and "SMTP.ogx".

Additionally, a sample project (one of those no-frills, 3-minute, to-hell-with-the-user jobbies) that zaps off a message is included. When extracting, be sure to "Use Folder Names".

These classes can be included into any MFC project. I've used them for ActiveX controls, ISAPI DLLs, and what have you. It's not inherently threadsafe so I either sprinkle CCrits around when I need them, or ensure that I only use _local_ CMessage and CSMTP objects.