NSString *url = [NSString stringWithString: @"mailto:foo@example.
com?cc=bar@example.com&subject=Greetings%20from%20Cupertino!&body=Wish%20you%20were%20here!"]; 
[[UIApplication sharedApplication] openURL: [NSURL URLWithString: url]]; 

#import <MessageUI/MFMailComposeViewController.h>; 
 
MFMailComposeViewController* controller = [[MFMailComposeViewController alloc] init]; 
controller.mailComposeDelegate = self; 
[controller setSubject:@"My Subject"]; 
[controller setMessageBody:@"Hello there." isHTML:NO]; 
[self presentModalViewController:controller animated:YES]; 
[controller release]; 
//使用该方法实现发送Email是最常规的方法，该方法有相应的MFMailComposeViewControllerDelegate事件: 
 
- (void)mailComposeController:(MFMailComposeViewController*)controller 
   didFinishWithResult:(MFMailComposeResult)result 
      error:(NSError*)error; 
{ 
 if (result == MFMailComposeResultSent) { 
 NSLog(@"It's away!"); 
 } 
 [self dismissModalViewControllerAnimated:YES]; 
} 
//有一些相关的数据结构的定义在头文件中都有具体的描述： 
 
enum MFMailComposeResult { 
 MFMailComposeResultCancelled,//用户取消编辑邮件 
 MFMailComposeResultSaved,//用户成功保存邮件 
 MFMailComposeResultSent,//用户点击发送，将邮件放到队列中 
 MFMailComposeResultFailed//用户试图保存或者发送邮件失败 
}; 
typedef enum MFMailComposeResult MFMailComposeResult; // iOS3.0以上有效 
//在头文件中MFMailComposeViewController的部分方法顺便提及： 
 
+ (BOOL)canSendMail __OSX_AVAILABLE_STARTING(__MAC_NA,__IPHONE_3_0); 
//如果用户没有设置邮件账户，则会返回NO，你可以用根据返回值来决定是使用MFMailComposeViewController 还是 mailto://的传统方法，也或者，你可以选择上文中提到的skpsmtpmessage来实现发送Email的功能。 
- (void)addAttachmentData:(NSData *)attachment mimeType:(NSString *)mimeType fileName:(NSString *)filename; 
//NSData类型的attachment自然不必多说，关于mimeType需要一点说明，官方文档里给出了一个链接http://www.iana.org/assignments/media-types/ ，这里列出的所有的类型都应该支持。关于mimeType的用处，更多需要依靠搜索引擎了 =] 

    SKPSMTPMessage *testMsg = [[SKPSMTPMessage alloc] init]; 
  testMsg.fromEmail = @"test@gmail.com"; 
  testMsg.toEmail =@"to@gmail.com"; 
  testMsg.relayHost = @"smtp.gmail.com"; 
  testMsg.requiresAuth = YES; 
  testMsg.login = @"test@gmail.com"; 
  testMsg.pass = @"test"; 
  testMsg.subject = [NSString stringWithCString:"测试" encoding:NSUTF8StringEncoding]; 
  testMsg.bccEmail = @"bcc@gmail.com"; 
  testMsg.wantsSecure = YES; // smtp.gmail.com doesn't work without TLS! 
 
  // Only do this for self-signed certs! 
  // testMsg.validateSSLChain = NO; 
  testMsg.delegate = self; 
 
  NSDictionary *plainPart = [NSDictionary dictionaryWithObjectsAndKeys:@"text/plain",kSKPSMTPPartContentTypeKey, 
         [NSString stringWithCString:"测试正文" encoding:NSUTF8StringEncoding],kSKPSMTPPartMessageKey,@"8bit",kSKPSMTPPartContentTransferEncodingKey,nil]; 
 
   NSString *vcfPath = [[NSBundle mainBundle] pathForResource:@"test" ofType:@"vcf"]; 
   NSData *vcfData = [NSData dataWithContentsOfFile:vcfPath]; 
 
   NSDictionary *vcfPart = [NSDictionary dictionaryWithObjectsAndKeys:@"text/directory;\r\n\tx-unix-mode=0644;\r\n\tname=\"test.vcf\"",kSKPSMTPPartContentTypeKey, 
          @"attachment;\r\n\tfilename=\"test.vcf\"",kSKPSMTPPartContentDispositionKey,[vcfData encodeBase64ForData],kSKPSMTPPartMessageKey,@"base64",kSKPSMTPPartContentTransferEncodingKey,nil]; 
 
  testMsg.parts = [NSArray arrayWithObjects:plainPart,vcfPart,nil]; 
 
  [testMsg send]; 
//该类也提供了相应的Delegate方法来让你更好的获知发送的状态. 
 
-(void)messageSent:(SKPSMTPMessage *)message; 
-(void)messageFailed:(SKPSMTPMessage *)message error:(NSError *)error;