试试下面这个函数：
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FUNCTION SendEMail(Handle : THandle; Mail : TStrings):Cardinal;
TYPE
TAttachAccessArray = ARRAY [0..0] OF TMapiFileDesc;
PAttachAccessArray = ^TAttachAccessArray;
VAR
MapiMessage : TMapiMessage;
Receip : TMapiRecipDesc;
Attachments : PAttachAccessArray;
AttachCount : INTEGER;
iCount : INTEGER;
FileName : STRING;
BEGIN
fillChar(MapiMessage, SizeOf(MapiMessage), #0);
Attachments := NIL;
fillChar(Receip,SizeOf(Receip), #0);
IF Mail.Values['to'] <> ''
THEN
BEGIN
Receip.ulReserved := 0;
Receip.ulRecipClass := MAPI_TO;
Receip.lpszName := StrNew(PChar(Mail.Values['to']));
Receip.lpszAddress := StrNew(PChar('SMTP:' + Mail.Values['to']));
Receip.ulEIDSize := 0;
MapiMessage.nRecipCount := 1;
MapiMessage.lpRecips := @Receip;
END;
AttachCount := 0;
FOR iCount := 0 TO MaxInt
DO
BEGIN
IF Mail.Values['attachment' + IntToStr(iCount)] = ''
THEN
BREAK;
AttachCount := AttachCount + 1;
END;
IF AttachCount > 0
THEN
BEGIN
GetMem(Attachments,SizeOf(TMapiFileDesc) * AttachCount);
FOR iCount := 0 TO (AttachCount - 1)
DO
BEGIN
FileName := Mail.Values['attachment' + IntToStr(iCount)];
Attachments[iCount].ulReserved := 0;
Attachments[iCount].flFlags := 0;
Attachments[iCount].nPosition := ULONG($FFFFFFFF);
Attachments[iCount].lpszPathName := StrNew(PChar(FileName));
Attachments[iCount].lpszFileName := StrNew(PChar(ExtractFileName(FileName)));
Attachments[iCount].lpFileType := NIL;
END;
MapiMessage.nFileCount := AttachCount;
MapiMessage.lpFiles := @Attachments^;
END;
IF Mail.Values['subject'] <> ''
THEN
MapiMessage.lpszSubject := StrNew(PChar(Mail.Values['subject']));
IF Mail.Values['body'] <> ''
THEN
MapiMessage.lpszNoteText := StrNew(PChar(Mail.Values['body']));
Result := MapiSendMail(0, Handle, MapiMessage,MAPI_DIALOG*Ord(Handle <> 0) OR MAPI_LOGON_UI OR MAPI_NEW_SESSION, 0);
FOR iCount := 0 TO (AttachCount - 1)
DO
BEGIN
strDispose(Attachments[iCount].lpszPathName);
strDispose(Attachments[iCount].lpszFileName);
END;
IF assigned(MapiMessage.lpszSubject)
THEN
strDispose(MapiMessage.lpszSubject);
IF assigned(MapiMessage.lpszNoteText)
THEN
strDispose(MapiMessage.lpszNoteText);
IF assigned(Receip.lpszAddress)
THEN
strDispose(Receip.lpszAddress);
IF assigned(Receip.lpszName)
THEN
strDispose(Receip.lpszName);
END;
