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
版权声明：可以任意转载，转载时请务必以超链接形式标明文章原始出处和作者信息及本声明。
http://www.cppblog.com/tuuzed/archive/2008/07/29/57477.html

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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[e-mail]发信给[e-mail]，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
 2 HMM_SOURCE_IP: 10.27 . 2.7 : 55493.2027099718
 3 HMM_ATTACHE_NUM: 0001
 4 HMM_SOURCE_TYPE:SMTP
 5 Received: from aisp7 - mta ? dg (dgproxy7.inner - hermes.com [ 10.27 . 2.7 ])
 6     by 21cn.com (HERMES) with SMTP id 359B63813A
 7      for   < [e-mail] > ; Tue,  29  Jul  2008   22 : 20 : 12   + 0800  (CST)
 8
 9 Received: 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
12 mx23749. 1217341212   for   < [e-mail] > ;
13     Tue,  11  Jul  2008   22 : 20 : 13   + 0000
14
15 X - Original - MailFrom: TestID@ 163 .com
16 Received: 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
 3 Reply - To: TestID@ 163 .com
 4
 5 From:  " TestID "   < TestID@ 163 .com >
 6 To:  " TestID2 "   < [e-mail] >
 7 Subject: Test Attachment
 8 Date: Tue,  29  Jul  2008   22 : 31 : 07   + 0800
 9 // Dreammail的识别ID
10 Message - Id:  < DreamMail__223107_76081071266@smtp. 163 .com >
11 MIME - Version:  1.0
12 // 内容类型及内容“指针ID”
13 Content - Type: multipart / mixed; 
14     boundary = " ----=_NextPart_08072922310693970267282_000 "
15 // 邮件优先级
16 X - Priority:  3
17 // 客户端名称
18 X - Mailer: DreamMail  4.4 . 1.0
19 X - 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
32 X - EsetId: 2080B02B6D6871693F86B07B643E31

 1 // 内容开始了，对应上面说的“指针ID”
 2 ------= _NextPart_08072922310693970267282_000
 3 Content - 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
 8 Content - Type: text / plain; 
 9     charset = " GB2312 "
10 Content - Transfer - Encoding: base64
11
12 SGVsbG8gV29ybGQhDQo =
13
14 // 有控制符、标签的HTML内容（BASE64编码）
15 ------= _NextPart_08072922310693970267282_002
16 Content - Type: text / html; 
17     charset = " GB2312 "
18 Content - Transfer - Encoding: base64
19
20 PEhUTUw + PEhFQUQ + PFRJVExFPk1haWw8L1RJVExFPg0KPE1FVEEgY29udGVudD0iS3NESFRNTEVE
21 TGliLm9jeCwgRnJlZVdhcmUgSFRNTCBFZGl0b3IgMS4xNjQuMiwgP0t1cnQgU2VuZmVyIiANCm5h
22 bWU9R0VORVJBVE9SPg0KPE1FVEEgaHR0cC1lcXVpdj1Db250ZW50LVR5cGUgY29udGVudD0idGV4
23 dC9odG1sOyBjaGFyc2V0PUdCMjMxMiI + PC9IRUFEPg0KPEJPRFkgc3R5bGU9IkZPTlQtU0laRTog
24 OXB0OyBGT05ULUZBTUlMWTogy87M5SIgbGVmdE1hcmdpbj01IHRvcE1hcmdpbj01ICNmZmZmZmY +
25 DQo8RElWPkhlbGxvIFdvcmxkITwhLS1BSURfU0VORFRPX0JFR0lOLS0 + PC9ESVY + PCEtLURyZWFt
26 TWFpbF9BRF9CRUdJTi0tPjxESVY + PEZPTlQgZmFjZT0iQXJpYWwsc2Fucy1zZXJpZiIgc2l6ZT0y
27 Pl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f
28 X19fX19fX19fX19fPEJSPjxFTT48U3Ryb25nPkRyZWFtTWFpbDwvU3Ryb25nPjwvRU0 + Jm5ic3A7
29 PEZPTlQgZmFjZT0iQXJpYWwsc2Fucy1zZXJpZiIgc2l6ZT0yPi0gtdrSu7j21qez1tPKvP7AtNS0
30 uPrX2bXEtefX09PKvP6 / zbuntssmbmJzcDs8L0ZPTlQ + PEZPTlQgZmFjZT0iQXJpYWwsc2Fucy1z
31 ZXJpZiIgY29sb3I9IzAwMDBmZiBzaXplPTI + PEEgaHJlZj0iaHR0cDovL3d3dy5kcmVhbW1haWwu
32 b3JnIj53d3cuZHJlYW1tYWlsLm9yZzwvQT48L0ZPTlQ + PC9GT05UPjwvRElWPjwhLS1EcmVhbU1h
33 aWxfQURfRU5ELS0 + PC9CT0RZPjwvSFRNTD4NCg ==
34
35 ------= _NextPart_08072922310693970267282_002 --
36 // 附件的内容
37 ------= _NextPart_08072922310693970267282_000
38 Content - Type: text / plain; 
39     name = " 1.txt "
40 Content - Transfer - Encoding: base64
41 Content - Disposition: attachment;
42     filename = " 1.txt "
43
44 MTIz
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 "
 13 TForm1  * Form1;
 14 // ---------------------------------------------------------------------------
 15 __fastcall TForm1::TForm1(TComponent *  Owner)
 16     : TForm(Owner)
 17 {
 18}
 19 // ---------------------------------------------------------------------------
 20 void  __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="[e-mail]";
 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 // ---------------------------------------------------------------------------
109 void  __fastcall TForm1::idSmtpConnected(TObject  * Sender)
110 {
111    btnSend->Enabled=false;    
112}
113 // ---------------------------------------------------------------------------
114 void  __fastcall TForm1::idSmtpDisconnected(TObject  * Sender)
115 {
116    btnSend->Enabled=true;
117}
118 // ---------------------------------------------------------------------------
119 void  __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 // ---------------------------------------------------------------------------
25 class  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 // ---------------------------------------------------------------------------
63 extern  PACKAGE TForm1  * Form1;
64 // ---------------------------------------------------------------------------
65 #endif
66

完成后编译试试！