利用Indy 10的IdSMTP控件制作可带附件的邮件发送器
作者：Tuuzed(土仔) 发表于：2008年7月29日
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http://www.cppblog.com/tuuzed/archive/2008/07/29/57477.html
Indy10中的IdSMTP控件比BCB6中自带的NMSMTP支持更多的SMTP命令（支持RFC 821,RFC 1869 ,RFC 2197 ,RFC 2554），像国内的网易、TOM、21CN等的SMTP都需要EHLO命令先进行认证才可使用。但是，目前很多大型的邮件服务商出于预防垃圾邮件的考虑，已经开始取消或限制SMTP发信了，改为提供WebMail服务，因此可用的SMTP服务器是少之又少了。有人说现在做SMTP邮件发送器意义已经不大，可我认为，动手去做这个SMTP发送器可以更好的了解一封电子邮件的结构和它的产生过程，管他别人爱说啥！
【邮件大致结构】
先用DreamMail发一封测试信：由TestID@163.com发信给TestID2@21cn.com，其中挂载附件1.txt。信件从21CN收回来之后是这样子的：
1
//服务器自动添加的东西
2HMM_SOURCE_IP:10.27.2.7:55493.2027099718
3HMM_ATTACHE_NUM:0001
4HMM_SOURCE_TYPE:SMTP
5Received: from aisp7-mta?dg (dgproxy7.inner-hermes.com [10.27.2.7])
6 by 21cn.com (HERMES) with SMTP id 359B63813A
7 for <TestID2@21cn.com>; Tue, 29 Jul 2008 22:20:12 +0800 (CST)
8
9Received: from m12-11.163.com([220.181.12.11])
10 by aisp7-mta@dg(Knowledge-based Antispam Gateway 2.126n5(2008-07-01),59.36.102.56) with ESMTP id
11
12mx23749.1217341212 for <TestID2@21cn.com>;
13 Tue, 11 Jul 2008 22:20:13 +0000
14
15X-Original-MailFrom: TestID@163.com
16Received: from ChinaPC (unknown [58.145.147.196])
17 by smtp7 (Coremail) with SMTP id C8CowLCrpS8XJ49IDQBdEQ==.5964S2;
18 Tue, 11 Jul 2008 22:20:07 +0800 (CST)
1//大都是我们自己填写的东西
2//回复地址
3Reply-To: TestID@163.com
4
5From: "TestID" <TestID@163.com>
6To: "TestID2" <TestID2@21cn.com>
7Subject: Test Attachment
8Date: Tue, 29 Jul 2008 22:31:07 +0800
9//Dreammail的识别ID
10Message-Id: <DreamMail__223107_76081071266@smtp.163.com>
11MIME-Version: 1.0
12//内容类型及内容“指针ID”
13Content-Type: multipart/mixed;
14 boundary="----=_NextPart_08072922310693970267282_000"
15//邮件优先级
16X-Priority: 3
17//客户端名称
18X-Mailer: DreamMail 4.4.1.0
19X-Coremail-Antispam: 1Uf129KBjDUn29KB7ZKAUJUUUUUYxn0WfASr-VFAUDa7-sFnT
20 9fnUUIcSsGvfJTRUUUj_xYjsxI4VWUJwAYFVCjjxCrM7AC8VAFwI0_Jr0_Gr1l1I0E4x80
21 FVCIwcAKzIAtM7C26IkvcIIF6IxKo4kEV4yl1IIY67AEw4v_Jr0_Jr4le4C267I2x7xF54
22 xIwI1l52xGzVA2a4k0FcxF6cIjj282cryl52xGzVA2a4k0FcxF6xCjrcI26cIUMc02F40E
23 57IF67AEF4xIwI1lYx0E2Ix0cI8IcVAFwI0_Jrv_JF1lYx0Ex4A2jsIE14v26r1j6r4UM4
24 xvF2IEb7IF0Fy264kE64k0F24lFcxC0VAYjxAxZF0Ex2IqxwAC62BYpTIE1TZKA3svLVAK
25 vSnIqfZI6r4lFVCF04k20xvEw2I207IF0wAKzVCY07xG64k0F24l7I0Y6sxI4wCY1Ik26c
26 xK620vw7xCY7Wlc7Ca8VAvwVCjb41lc7Ca8VAvwVCFzxkY4VA2I41lc2xSY4AK67AK6ry5
27 MxkI7II2jI8vz4v_Jr0_Jryl4x8a6c8ajcxJMI8E67AF67kF1VAFwI0_Jr0_JrylIxAIcV
28 C0I7IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Jr0_Gr1lIxAIcVC2
29 z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxVWUJVW8JbIYCTnIWIevJa73Uj
30 IFyTuYvjxUgg4SUUUUU
31//ESet病毒防火墙添加
32X-EsetId: 2080B02B6D6871693F86B07B643E31
1//内容开始了，对应上面说的“指针ID”
2------=_NextPart_08072922310693970267282_000
3Content-Type: multipart/alternative;
4 boundary="----=_NextPart_08072922310693970267282_002"
5
6//无控制符、无标签的文本内容（BASE64编码）
7------=_NextPart_08072922310693970267282_002
8Content-Type: text/plain;
9 charset="GB2312"
10Content-Transfer-Encoding: base64
11
12SGVsbG8gV29ybGQhDQo=
13
14//有控制符、标签的HTML内容（BASE64编码）
15------=_NextPart_08072922310693970267282_002
16Content-Type: text/html;
17 charset="GB2312"
18Content-Transfer-Encoding: base64
19
20PEhUTUw+PEhFQUQ+PFRJVExFPk1haWw8L1RJVExFPg0KPE1FVEEgY29udGVudD0iS3NESFRNTEVE
21TGliLm9jeCwgRnJlZVdhcmUgSFRNTCBFZGl0b3IgMS4xNjQuMiwgP0t1cnQgU2VuZmVyIiANCm5h
22bWU9R0VORVJBVE9SPg0KPE1FVEEgaHR0cC1lcXVpdj1Db250ZW50LVR5cGUgY29udGVudD0idGV4
23dC9odG1sOyBjaGFyc2V0PUdCMjMxMiI+PC9IRUFEPg0KPEJPRFkgc3R5bGU9IkZPTlQtU0laRTog
24OXB0OyBGT05ULUZBTUlMWTogy87M5SIgbGVmdE1hcmdpbj01IHRvcE1hcmdpbj01ICNmZmZmZmY+
25DQo8RElWPkhlbGxvIFdvcmxkITwhLS1BSURfU0VORFRPX0JFR0lOLS0+PC9ESVY+PCEtLURyZWFt
26TWFpbF9BRF9CRUdJTi0tPjxESVY+PEZPTlQgZmFjZT0iQXJpYWwsc2Fucy1zZXJpZiIgc2l6ZT0y
27Pl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f
28X19fX19fX19fX19fPEJSPjxFTT48U3Ryb25nPkRyZWFtTWFpbDwvU3Ryb25nPjwvRU0+Jm5ic3A7
29PEZPTlQgZmFjZT0iQXJpYWwsc2Fucy1zZXJpZiIgc2l6ZT0yPi0gtdrSu7j21qez1tPKvP7AtNS0
30uPrX2bXEtefX09PKvP6/zbuntssmbmJzcDs8L0ZPTlQ+PEZPTlQgZmFjZT0iQXJpYWwsc2Fucy1z
31ZXJpZiIgY29sb3I9IzAwMDBmZiBzaXplPTI+PEEgaHJlZj0iaHR0cDovL3d3dy5kcmVhbW1haWwu
32b3JnIj53d3cuZHJlYW1tYWlsLm9yZzwvQT48L0ZPTlQ+PC9GT05UPjwvRElWPjwhLS1EcmVhbU1h
33aWxfQURfRU5ELS0+PC9CT0RZPjwvSFRNTD4NCg==
34
35------=_NextPart_08072922310693970267282_002--
36//附件的内容
37------=_NextPart_08072922310693970267282_000
38Content-Type: text/plain;
39 name="1.txt"
40Content-Transfer-Encoding: base64
41Content-Disposition: attachment;
42 filename="1.txt"
43
44MTIz
45
46------=_NextPart_08072922310693970267282_000--
看完之后应该对邮件结构有个大致的印象了，其实不难，牛人通常都是把各种值自己填充完，然后用winsocket发出去的。只是都喜欢偷懒，Indy已经帮忙包装好了，只管用就OK。
【准备工作】
准备啥呢？已经安装好最新版Indy10的BCB6、一个可以使用SMTP端口的邮件帐号和一条可以上网的线路。
【了解所需的控件】
TIdSMTP中的属性名称都很清楚（服务器地址、端口、认证类型、登录超时等），无需再多说。发信最关键是要用到控件的两个方法：Connect和Send。Connect（AnsiString ServerAddress, AnsiString ServerPort）方法实现的是登录SMTP服务器和用户名认证；Send（TIdMessage *AMsg）方法实现的是认证后的发信过程，AMsg指的是信件的内容，也就是与上面所看到类似的信件源码，它是Indy10中的TIdMessage类指针。
TIdMessage属性大致归两类，一是邮件头：就是寄信人、收信人、抄送、密送、主题、信件内容编码、附件编码等；二是邮件内容：包括无控制符无标签的纯文本内容(Plain)、带控制符带标签的网页内容(Html)、编码后的附件(Attachment)。Indy10中，Plain和Html用TIdText类实现，Attachment用TIdAttachmentFile实现。只要将两个类实例化并挂载在TIdMessage下，就组成一个完整的邮件内容了。
【开始动手】
一个很简陋的界面：
堆上比较容易理解的代码：
1//main.cpp
2//---------------------------------------------------------------------------
3
4#include <vcl.h>
5#pragma hdrstop
6
7#include "Main.h"
8//---------------------------------------------------------------------------
9#pragma package(smart_init)
10#pragma link "IdExplicitTLSClientServerBase"
11#pragma link "IdSMTPBase"
12#pragma resource "*.dfm"
13TForm1 *Form1;
14//---------------------------------------------------------------------------
15__fastcall TForm1::TForm1(TComponent* Owner)
16 : TForm(Owner)
17
{
18
}
19//---------------------------------------------------------------------------
20void __fastcall TForm1::btnSendClick(TObject *Sender)
21{
22
//Mail
23 TIdText *idBody, *idHtml;
24 TIdAttachmentFile *idAtta;
25 try
26
{
27
28 idMsg=new TIdMessage(Application);
29 //Msg base header
30 idMsg->From->Name=edtName->Text.Trim();
31 idMsg->From->Address=edtMailaddr->Text.Trim();
32 idMsg->ReplyTo->EMailAddresses="no_reply@163.com";
33 idMsg->ContentType="multipart/alternative";
34 idMsg->ContentTransferEncoding="base64";
35 idMsg->AttachmentEncoding="MIME";
36 idMsg->Encoding=meDefault;
37 idMsg->CharSet="gb2312";
38 idMsg->Subject=edtSubject->Text.Trim();
39 idMsg->Recipients->EMailAddresses=edtTo->Text.Trim();
40 idMsg->Priority=mpNormal;
41
42 //msg body plain
43 idBody=new TIdText(idMsg->MessageParts, idMsg->Body);
44 idBody->CharSet="utf-8";
45 idBody->ContentType="text/plain";
46 idBody->ContentTransfer="base64";
47 idBody->Body->Add(mmoContent->Text);
48
49 //msg body html
50 idHtml=new TIdText(idMsg->MessageParts, idMsg->Body);
51 idHtml->CharSet="utf-8";
52 idHtml->ContentType="text/html";
53 idHtml->ContentTransfer="base64";
54 idHtml->Body->Add("<HTML><HEAD><TITLE>Mail</TITLE></HEAD>");
55 idHtml->Body->Add("<BODY>");
56 idHtml->Body->Add(mmoContent->Text);
57 idHtml->Body->Add("</BODY></HTML>");
58
59 //msg body attachment
60 if (edtAttach->Text.Trim()!="")
61 {
62 if (FileExists(edtAttach->Text.Trim()))
63 {
64 idAtta=new TIdAttachmentFile(idMsg->MessageParts, edtAttach->Text.Trim());
65
66 idAtta->ContentType="application/octet-stream";
67 idAtta->ContentDisposition="attachment";
68 idAtta->ContentTransfer="base64";
69 idAtta->FileName=ExtractFileName(edtAttach->Text.Trim());
70
}
71 else
72 {
73 edtAttach->Text="";
74 }
75 }
76 }
77 catch(Exception &exception)
78 {
79 //show Error!
80 idMsg->Clear();
81 delete idMsg;
82 return;
83 }
84
85 //SMTP Server
86 try
87 {
88 idSmtp->Username=edtUsername->Text;
89 idSmtp->Password=edtPasswd->Text;
90 idSmtp->HeloName="SMTP";
91 idSmtp->MailAgent="DreamMail";
92 idSmtp->UseEhlo=true;
93 idSmtp->ReadTimeout=5000;
94 idSmtp->Connect(edtServer->Text, StrToInt(edtPort->Text));
95 idSmtp->Send(idMsg);
96 }
97 catch()
98 {
99 //Show error!
100 idSmtp->Disconnect();
101 delete idMsg;
102 return;
103 }
104 idSmtp->Disconnect();
105 delete idMsg;
106 ShowMessage("Mail Sent!");
107}
108//---------------------------------------------------------------------------
109void __fastcall TForm1::idSmtpConnected(TObject *Sender)
110{
111 btnSend->Enabled=false;
112}
113//---------------------------------------------------------------------------
114void __fastcall TForm1::idSmtpDisconnected(TObject *Sender)
115{
116 btnSend->Enabled=true;
117}
118//---------------------------------------------------------------------------
119void __fastcall TForm1::btnOpenfileClick(TObject *Sender)
120{
121 try
122 {
123 TOpenDialog *opdGetfile=new TOpenDialog(Application);
124 opdGetfile->Options.Clear();
125 opdGetfile->Title = "Select attachment";
126 opdGetfile->Options << ofFileMustExist;
127 opdGetfile->InitialDir=ExtractFilePath(Application->ExeName);
128 opdGetfile->Filter = "All files (*.*)|*.*";
129 opdGetfile->FilterIndex = 2;
130 if(opdGetfile->Execute())
131 {
132 if (FileExists(opdGetfile->FileName))
133 edtAttach->Text=opdGetfile->FileName;
134
135 }
136 }
137 catch()
138 {
139 return;
140 }
141
142
143}
144//---------------------------------------------------------------------------
145
1//main.h
2//---------------------------------------------------------------------------
3
4#ifndef MainH
5#define MainH
6//---------------------------------------------------------------------------
7#include <Classes.hpp>
8#include <Controls.hpp>
9#include <StdCtrls.hpp>
10#include <Forms.hpp>
11#include "IdExplicitTLSClientServerBase.hpp"
12#include "IdSMTPBase.hpp"
13#include <IdBaseComponent.hpp>
14#include <IdComponent.hpp>
15#include <IdMessageClient.hpp>
16#include <IdSMTP.hpp>
17#include <IdTCPClient.hpp>
18#include <IdTCPConnection.hpp>
19#include <IdText.hpp> //TIdText needed
20#include <IdAttachmentFile.hpp> //TIdAttachment needed
21//#include <IdMessageCoderMIME.hpp>
22#include <IdCoderHeader.hpp>
23
24//---------------------------------------------------------------------------
25class TForm1 : public TForm
26{
27__published: // IDE-managed Components
28 TGroupBox *grpServer;
29 TEdit *edtServer;
30 TEdit *edtPort;
31 TEdit *edtUsername;
32 TEdit *edtPasswd;
33 TIdSMTP *idSmtp;
34 TGroupBox *grpMail;
35 TEdit *edtName;
36 TEdit *edtMailaddr;
37 TEdit *edtTo;
38 TEdit *edtSubject;
39 TMemo *mmoContent;
40 TButton *btnSend;
41 TEdit *edtAttach;
42 TButton *btnOpenfile;
43 TLabel *lbl1;
44 TLabel *lbl2;
45 TLabel *lbl3;
46 TLabel *lbl4;
47 TLabel *lbl5;
48 TLabel *lbl6;
49 TLabel *lbl7;
50 TLabel *lbl8;
51 TLabel *lbl9;
52 void __fastcall btnSendClick(TObject *Sender);
53 void __fastcall idSmtpConnected(TObject *Sender);
54 void __fastcall idSmtpDisconnected(TObject *Sender);
55 void __fastcall btnOpenfileClick(TObject *Sender);
56private: // User declarations
57 TIdMessage *idMsg;
58 //TIdMessageEncoderMIME *idMsg;
59public: // User declarations
60 __fastcall TForm1(TComponent* Owner);
61};
62//---------------------------------------------------------------------------
63extern PACKAGE TForm1 *Form1;
64//---------------------------------------------------------------------------
65#endif
66
完成后编译试试！