Basic SMTP using Winsock and Delphi

[Martin Berriman]

I'm trying to use SMTP with a basic Winsock implementation rather than a
complete (and bulky) component. It is very simple to do in "C" in a small
number of lines but I have not managed to get it working in Delphi3. I have
included the delphi code below.

Everything is fine until the "connect" line whereupon I get a return value
of SOCKET_ERROR - using WSAGetLastError returns 0.

The same code (allowing for syntax) works very well in borland C 5.02.

Any ideas? (sorry the formatting has gone a bit wrong below)
Thanks in advance.

function smtp_connect(server : PChar) : Integer;
var
wsadata : TWSADATA;
Hostent : PHostEnt;
nb : LongInt;
ok : Integer;
server_addr : TSockAddrIn;
begin
if (WSAStartup($0101, wsadata) <> 0) then
begin
ShowMessage('Unable to open WINSOCK');
Exit;
end;

s := socket(AF_INET, SOCK_STREAM, 0);
if (s = INVALID_SOCKET) then
begin
ShowMessage('Unable to create socket');
Exit;
end;

nb := 1;
ioctlsocket(s, FIONBIO, nb);

Hostent := gethostbyname(server);
if Hostent = nil then
begin
ShowMessage('Host not found');
Exit;
end;

server_addr.sin_family := AF_INET;
server_addr.sin_port := htons (25);

with server_addr.sin_addr.S_un_b, Hostent^ do
begin
s_b1 := h_addr^[0];
s_b2 := h_addr^[1];
s_b3 := h_addr^[2];
s_b4 := h_addr^[3];
end;

ok := connect(s, server_addr, SizeOf(server_addr));
if (ok <> 0) then
begin
ShowMessage('Connect Failed (' + IntToStr(ok) + ')');
Result := -1;
if (ok = SOCKET_ERROR) then ShowMessage('Socket Error');
end
else Result := 0;
end;

Where the socket is described as follows:
var
s : TSocket;

[Alun Jones]

In article <aa75v0$hj0$1...@paris.btinternet.com>, "Martin Berriman"

<mar...@berriman.co.uk> wrote:
>Everything is fine until the "connect" line whereupon I get a return value
>of SOCKET_ERROR - using WSAGetLastError returns 0.

The usual cause of incorrect WSAGetLastError() results is that you've called
some other API function between the Winsock function and the call to
WSAGetLastError. In Win32, WSAGetLastError is an alias for GetLastError.

Alun.
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