string host = "smtp.gmail.com";
int port;
//port = 587; // with TLS
//port = 465; // with SSL
port = 25; // normal - works for my gmail account with enableSSL
string fromEmail = "[email protected]";
var fromAddress = new MailAddress(fromEmail);
var toAddress = new MailAddress("[email protected]");
MailMessage message = new MailMessage(fromAddress, toAddress)
{
	Subject = "subject",
	Body = "body",
};
var smtp = new SmtpClient(host, port) {
	Credentials=new NetworkCredential(fromEmail, "password"),
	EnableSsl = true,
	Timeout = 30000,
};

try {
smtp.Send(message);
}
catch(SmtpException se) {
//log
}
message.Dispose();

http://www.google.com/support/forum/p/Google+Apps/thread?tid=3abf482d7d7e24d3&hl=en&fid=3abf482d7d7e24d3000484c10943499b

For both gmail and gApps, use smtp.gmail.com on port 25 with SSL and NetworkCredentials.

Neither can send email to their own address, but they can send to other addresses.

[NLog](http://nlog-project.org/) has [an example](http://nlog-project.org/wiki/Using_NLog_with_GMail) of how to automatically send emails in order to log info from an app.

Sending emails (particularly with gmail and google apps for domains)

email

C#