邮件发送程序编写教程

主讲：上兴 邮件发送演示，演示直接根据RFC协议进行发信 演示利用空间中转邮件 1。直接根据RFC协议进行发信 ///////////////////////////////////////////////////////////////////////// 首先将常用的网络操作单元集合为一个单元 Unit_MyWinSock.pas //////////////////////////////////////////////////////////////////////// unit Unit_MyWinSock; interface uses Windows, WinSock; function GetIpbyHostName(Host: string): string; function StartNet(host: string; port: integer; var FSocket: integer): Boolean; procedure StopNet(Fsocket: integer); function SendData(FSocket: integer; SendStr: string): integer; function GetData(FSocket: integer): string; implementation function StrPas(const Str: PChar): string; begin Result := Str; end; function StrCopy(Dest: PChar; const Source: PChar): PChar; asm PUSH EDI PUSH ESI MOV ESI,EAX MOV EDI,EDX MOV ECX,0FFFFFFFFH XOR AL,AL REPNE SCASB NOT ECX MOV EDI,ESI MOV ESI,EDX MOV EDX,ECX MOV EAX,EDI SHR ECX,2 REP MOVSD MOV ECX,EDX AND ECX,3 REP MOVSB POP ESI POP EDI end; function StrLen(const Str: PChar): Cardinal; assembler; asm MOV EDX,EDI MOV EDI,EAX MOV ECX,0FFFFFFFFH XOR AL,AL REPNE SCASB MOV EAX,0FFFFFFFEH SUB EAX,ECX MOV EDI,EDX end; {============================================================} function GetIpbyHostName(Host: string): string; { 功能描述:获取主机的IP地址 } type TaPInAddr = array[0..10] of PInAddr; PaPInAddr = ^TaPInAddr; var phe: PHostEnt; pptr: PaPInAddr; i: Integer; begin Result := ''; phe := GetHostByName(pchar(Host)); if phe = nil then Exit; pptr := PaPInAddr(Phe^.h_addr_list); I := 0; while pptr^[I] <> nil do begin if i = 0 then result := StrPas(inet_ntoa(pptr^[I]^)); Inc(I); end; end; {============================================================} function StartNet(host: string; port: integer; var FSocket: integer): Boolean; { 功能描述:连接某IP地址 } var SockAddrIn: TSockAddrIn; t: linger; timeout: timeval; r: TFDSet; iTimeOut: integer; ul, ul1: LongInt; ret: integer; begin Result := False; FSocket := socket(PF_INET, SOCK_STREAM, IPPROTO_IP); if FSocket = invalid_socket then exit; t.l_onoff := 1; t.l_linger := 0; setsockopt(FSocket, SOL_SOCKET, SO_LINGER, @t, sizeof(t)); {关闭Socket后立刻释放资源} //set Recv and Send time out iTimeOut := 6000; //设置发送超时6秒 if (setsockopt(FSocket, SOL_SOCKET, SO_SNDTIMEO, @iTimeOut, sizeof(TimeOut)) = SOCKET_ERROR) then Exit; iTimeOut := 6000; //设置接收超时6秒 if (setsockopt(FSocket, SOL_SOCKET, SO_RCVTIMEO, @iTimeOut, sizeof(TimeOut)) = SOCKET_ERROR) then Exit; //设置非阻塞方式连接 ul := 1; ret := ioctlsocket(FSocket, FIONBIO, ul); if (ret = SOCKET_ERROR) then Exit; //连接 SockAddrIn.sin_addr.s_addr := inet_addr(PChar(host)); SockAddrIn.sin_family := PF_INET; SockAddrIn.sin_port := htons(port); ret := connect(FSocket, SockAddrIn, SizeOf(SockAddrIn)); //select 模型，即设置超时 FD_ZERO(r); FD_SET(FSocket, r); timeout.tv_sec := 5; //连接超时5秒 timeout.tv_usec := 0; ret := select(0, nil, @r, nil, @timeout); if (ret <= 0) then begin closesocket(FSocket); Exit; end; //一般非锁定模式套接比较难控制，可以根据实际情况考虑 再设回阻塞模式 ul1 := 0; ret := ioctlsocket(FSocket, FIONBIO, ul1); if (ret = SOCKET_ERROR) then begin closesocket(FSocket); Exit; end; Result := True; end; {============================================================} procedure StopNet(Fsocket: integer); { 功能描述:关闭一个Socket } begin closesocket(FSocket); end; {============================================================} function SendData(FSocket: integer; SendStr: string): integer; { 功能描述:通过指定Socket发送字符数据 } var DataBuf: array[0..4096] of char; err: integer; begin strcopy(DataBuf, pchar(SendStr)); err := send(FSocket, DataBuf, strlen(DataBuf), MSG_DONTROUTE); Result := err; end; {============================================================} function GetData(FSocket: integer): string; { 功能描述:获取指定Socket的字符数据 } const MaxSize = 1024; var DataBuf: array[0..MaxSize] of char; err: integer; begin err := recv(FSocket, DataBuf, MaxSize, 0); Result := Strpas(DataBuf); end; { const MaxSize = 1024; var DataBuf: array[0..MaxSize - 1] of char; S: string; iRet: integer; begin S := ''; repeat FillChar(DataBuf, MaxSize, #0); iRet := recv(FSocket, DataBuf, MaxSize, 0); S := S + Strpas(DataBuf); until iRet <= 0; Result := S; end; } {============================================================} var Re: integer; Wsa: TWSAData; initialization Re := WSAStartup($101, Wsa); //初始化Wsock32.dll,如果是2.2版本,则使用MakeWord(2,2), if Re <> 0 then Halt; finalization WSACleanUp; end. //////////////////////////////////////////////////////////////////////////////////// 和Base64编码Delphi版本 BASE64.pas ///////////////////////////////////////////////////////////////////////////////////// unit BASE64; interface uses Classes; //BaseTable为BASE64码表 const BaseTable:string='ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/='; function EncodeStringBase64(Source:string):string; function DecodeStringBASE64(Source:string):string; function EncodeStreamBASE64(Encoded: TMemoryStream ; Decoded: TMemoryStream): Integer; implementation {对参数TMemoryStrema中的字节流进行Base64编码，编码后的结果保存在Encoded中，函数返回编码长度} function EncodeStreamBASE64(Encoded: TMemoryStream ; Decoded: TMemoryStream): Integer; const _Code64: String[64] =('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'); var I: LongInt; B: array[0..2279] of Byte; J, K, L, M, Quads: Integer; Stream: string[76]; EncLine: String; begin Encoded.Clear; Stream := ''; Quads := 0; {为提高效率，每2280字节流为一组进行编码} J := Decoded.Size div 2280; Decoded.Position := 0; {对前J*2280个字节流进行编码} for I := 1 to J do begin Decoded.Read(B, 2280); for M := 0 to 39 do begin for K := 0 to 18 do begin L:= 57*M + 3*K; Stream[Quads+1] := _Code64[(B[L] div 4)+1]; Stream[Quads+2] := _Code64[(B[L] mod 4)*16 + (B[L+1] div 16)+1]; Stream[Quads+3] := _Code64[(B[L+1] mod 16)*4 + (B[L+2] div 64)+1]; Stream[Quads+4] := _Code64[B[L+2] mod 64+1]; Inc(Quads, 4); if Quads = 76 then begin Stream[0] := #76; EncLine := Stream+#13#10; Encoded.Write(EncLine[1], Length(EncLine)); Quads := 0; end; end; end; end; {对以2280为模的余数字节流进行编码} J := (Decoded.Size mod 2280) div 3; for I := 1 to J do begin Decoded.Read(B, 3); Stream[Quads+1] := _Code64[(B[0] div 4)+1]; Stream[Quads+2] := _Code64[(B[0] mod 4)*16 + (B[1] div 16)+1]; Stream[Quads+3] := _Code64[(B[1] mod 16)*4 + (B[2] div 64)+1]; Stream[Quads+4] := _Code64[B[2] mod 64+1]; Inc(Quads, 4); {每行76个字符} if Quads = 76 then begin Stream[0] := #76; EncLine := Stream+#13#10; Encoded.Write(EncLine[1], Length(EncLine)); Quads := 0; end; end; {“=”补位} if (Decoded.Size mod 3) = 2 then begin Decoded.Read(B, 2); Stream[Quads+1] := _Code64[(B[0] div 4)+1]; Stream[Quads+2] := _Code64[(B[0] mod 4)*16 + (B[1] div 16)+1]; Stream[Quads+3] := _Code64[(B[1] mod 16)*4 + 1]; Stream[Quads+4] := '='; Inc(Quads, 4); end; if (Decoded.Size mod 3) = 1 then begin Decoded.Read(B, 1); Stream[Quads+1] := _Code64[(B[0] div 4)+1]; Stream[Quads+2] := _Code64[(B[0] mod 4)*16 + 1]; Stream[Quads+3] := '='; Stream[Quads+4] := '='; Inc(Quads, 4); end; Stream[0] := Chr(Quads); if Quads > 0 then begin EncLine := Stream+#13#10; Encoded.Write(EncLine[1], Length(EncLine)); end; Result := Encoded.Size; end; function FindInTable(CSource:char):integer; begin result:=Pos(string(CSource),BaseTable)-1; end; //// {对参数Source字符串进行Base64编码，返回编码后的字符串} function DecodeStringBASE64(Source:string):string; var SrcLen,Times,i:integer; x1,x2,x3,x4,xt:byte; begin result:=''; SrcLen:=Length(Source); Times:=SrcLen div 4; for i:=0 to