MAPISendMail access violation - delphi

Question

I have a problem with MapiSendMail function of MAPI32.dll. Everything seems fine, message is completed, then I send it by winapi function, and i get an Access violation error, it happend in MAPISendMail. Here's the fragment of the code:
MAPIModule := LoadLibrary(PWideChar(MAPIDLL));
if MAPIModule = 0 then
Result := -1
else
try
#SM := GetProcAddress(MAPIModule, 'MAPISendMail');
if #SM <> nil then
begin
Result := SM(0, application.Handle, Msg, MAPI_DIALOG {or MAPI_LOGON_UI}, 0);
end
else
Result := 1;
finally
end;
Also I was trying to change GetProcAddres to MAPISendMailW or MAPISendMailHelper, but then #SM was nil.
#Edit1
function TMail._SendMAPIEmail(const aTo, aAtts: array of AnsiString; const body, subject, SenderName, SenderEmail: string; ShowError: Boolean = true): Integer;
var
SM: TFNMapiSendMail;
Msg: MapiMessage;
lpSender: MapiRecipDesc;
Recips: array of MapiRecipDesc;
Att: array of MapiFileDesc;
TempAttNames: array of pAnsiChar;
TempAttNamesAnsi: array of AnsiString;
TempAttPaths: array of pAnsiChar;
TempRecip: array of pAnsiChar;
p1, LenTo, LenAtts: Integer;
MAPIModule: HModule;
sError: String;
i: integer;
begin
try
FillChar(Msg, SizeOf(Msg), 0);
{ get the length of all arrays passed to this function }
LenTo := length(aTo);
if Trim(aAtts[0]) <> '' then
LenAtts := length(aAtts)
else
LenAtts := 0;
{ ... }
SetLength(Recips, LenTo);
SetLength(TempRecip, LenTo);
Setlength(Att, LenAtts);
SetLength(TempAttNames, LenAtts);
SetLength(TempAttPaths, LenAtts);
SetLength(TempAttNamesAnsi, LenAtts);
{ to }
for p1 := 0 to LenTo - 1 do
begin
FillChar(Recips[p1], SizeOf(Recips[p1]), 0);
Recips[p1].ulReserved := 0;
Recips[p1].ulRecipClass := MAPI_TO;
{ Upgrade }
Recips[p1].lpszName := '';
TempRecip[p1] := pAnsichar(aTo[p1]);
Recips[p1].lpszAddress := TempRecip[p1];
end;
{ atts }
for p1 := 0 to LenAtts - 1 do
begin
FillChar(Att[p1], SizeOf(Att[p1]), 0);
FillChar(TempAttPaths[p1], SizeOf(pAnsiChar), 0);
FillChar(TempAttNames[p1], SizeOf(pAnsiChar), 0);
FillChar(TempAttNamesAnsi[01], SizeOf(AnsiChar), 0);
Att[p1].ulReserved := 0;
Att[p1].flFlags := 0;
Att[p1].nPosition := Cardinal($FFFFFFFF);
{ Upgrade }
TempAttPaths[p1] := pAnsichar(aAtts[p1]);
Att[p1].lpszPathName := TempAttPaths[p1];
TempAttNamesAnsi[p1] := AnsiString((ExtractFileName(string(aAtts[p1]))));
TempAttNames[p1] := pAnsiChar(TempAttNamesAnsi[p1]);
Att[p1].lpszFileName := TempAttNames[p1];
end;
{ fill the message }
with Msg do
begin
ulReserved := 0;
if subject <> '' then
{ Upgrade }
lpszSubject := pAnsichar(AnsiString(subject));
if body <> '' then
{ Upgrade }
lpszNoteText := pAnsichar(AnsiString(body));
if SenderEmail <> '' then
begin
lpSender.ulRecipClass := MAPI_ORIG;
if SenderName = '' then
lpSender.lpszName := pAnsichar(AnsiString(SenderEmail))
else
lpSender.lpszName := pAnsichar(AnsiString(SenderName));
lpSender.lpszAddress := pAnsichar(AnsiString(SenderEmail));
lpSender.ulEIDSize := 0;
lpSender.lpEntryID := nil;
lpOriginator := #lpSender;
end
else
Msg.lpOriginator := nil;
Msg.lpszMessageType := nil;
Msg.lpszDateReceived := nil;
Msg.lpszConversationID := nil;
Msg.flFlags := 0;
Msg.nRecipCount := LenTo;
Msg.lpRecips := #Recips[0];
Msg.nFileCount := LenAtts;
Msg.lpFiles := #Att[0];
end;
MAPIModule := LoadLibrary(PWideChar(MAPIDLL));
if MAPIModule = 0 then
Result := -1
else
try
#SM := GetProcAddress(MAPIModule, 'MAPISendMail');
if #SM <> nil then
begin
//Result := MapiSendMail(0, application.Handle, Msg, MAPI_DIALOG, 0);
Result := SM(0, 0, Msg, MAPI_DIALOG {or MAPI_LOGON_UI}, 0);
end
else
Result := 1;
finally
if Assigned(Att) and (Msg.nFileCount > 0) then
begin
for i := 0 to Msg.nFileCount - 1 do
begin
if Assigned(Att[i].lpszPathName) then
Att[i].lpszPathName := nil;
if Assigned(Att[i].lpszFileName) then
Att[i].lpszFileName := nil;
//FreeMem(Att[i].lpszPathName);
//Dispose(Att[i].lpszPathname);
//StrDispose(Att[i].lpszPathName);
//Dispose(Att[i].lpszFileName);
//StrDispose(Att[i].lpszFileName);
end;
Att := nil;
end;
if Assigned(Recips) and (Msg.nRecipCount > 0) then
begin
for i := 0 to Msg.nRecipCount - 1 do
begin
if Assigned(Recips[i].lpszName) then
Recips[i].lpszName := nil;
if Assigned(Recips[i].lpszAddress) then
Recips[i].lpszAddress := nil;
//if Assigned(Recips[i].lpszName) then
//Dispose(Recips[i].lpszName);
//if Assigned(Recips[i].lpszAddress) then
//Dispose(Recips[i].lpszAddress);
end;
Recips := nil;
end;
end;

Answer 1

Under Win32
Under Win32 it should not be a problem. Just first try calling MapiSendMail with very simple MapiMessage and if it will work, add complexity little by little. Your code is just too complex to debug it visually. Did you call MapiSendMail with very simple MapiMessage, just for testing? Please try the following code, it works for sure:
procedure TestSendExA(const APath1, ACaption1, APath2, ACaption2: AnsiString);
var
R: Integer;
MSG: TMapiMessage;
F: Array [0..1] of TMapiFileDesc;
Recipients: array[0..1] of TMapiRecipDesc;
Originator : array[0..0] of TMapiRecipDesc;
begin
if not FileExists(APath1) or not FileExists(APath2) then raise Exception.Create('File not found');
FillChar(Msg, SizeOf(Msg), 0);
Msg.lpszSubject := 'testo';
Msg.lpszNoteText := 'Hi there!';
Msg.lpszDateReceived := '2015/01/25 12:34';
Msg.lpszConversationId := '1234.test#ritlabs.com';
Msg.flFlags := MAPI_RECEIPT_REQUESTED;
FillChar(Recipients, SizeOf(Recipients), 0);
with Recipients[0] do
begin
ulRecipClass := MAPI_TO;
lpszName := 'Maxim Masiutin';
lpszAddress := 'maxim.test#ritlabs.com';
end;
with Recipients[1] do
begin
ulRecipClass := MAPI_CC;
lpszName := 'Vasilii Pupkin';
lpszAddress := 'pupkin.test#ritlabs.com';
end;
FillChar(Originator, SizeOf(Originator), 0);
with Originator[0] do
begin
ulRecipClass := MAPI_TO;
lpszName := 'Maxim Masiutin';
lpszAddress := 'max#ritlabs.com';
end;
Msg.lpOriginator := #Originator;
Msg.nRecipCount := 2;
Msg.lpRecips := #Recipients;
Msg.nFileCount := 2;
Msg.lpFiles := #F;
FillChar(F, SizeOf(F), 0);
F[0].lpszPathName := PAnsiChar(APath1);
F[0].lpszFileName := PAnsiChar(ACaption1);
F[1].lpszPathName := PAnsiChar(APath2);
F[1].lpszFileName := PAnsiChar(ACaption2);
R := MAPISendMail(MapiSession, 0, Msg, 0, 0);
end;
The MapiSession in the above example is a handle to the session returned by MapiLogon.
This sample code requires that you pass two valid file paths to valid files in APath1 and APath2.
Under Win64
It is the record alignment of MapiMessage and other records that it is important when you work with Simple MAPI from Delphi: (1) make sure the records don't have "packed" prefix; and (2) make sure you have {$A8} compiler directive is explicitly specified before first record definition. This will work fine under both Win32 and Win64.