Ho utilizzato questo codice( librerie oeapi) per creare messaggi email da spedire con allegati pdf...

public int Crea(Messaggio messaggio)
{
OEMessage m;
OEFolderManager fm = new OEFolderManager();
OEFolder f;
string msg;

f = OttieniCartella("Posta in uscita");
if (f == null)
return -1;

msg = "From:" + messaggio.MITTENTE + Environment.NewLine;
msg += "Subject:" + messaggio.OGGETTO + Environment.NewLine;
msg += "To:" + messaggio.DESTINAZIONE + Environment.NewLine + Environment.NewLine;
msg += messaggio.TESTO;

try
{
m = f.CreateMessage(msg, 0);
m.AttachFile(messaggio.ALLEGATO);
m.Commit();
f = fm.GetOutboxFolder();
m.SetFolderID(f.GetID());
obj.SendMessage(f.GetID(), m.GetID());
m.Commit();
m.Delete(1);
return 0;
}
catch (Exception ex)
{
return -1;
}
}

le email vengono create normalmente e anche inviate.
Il problema è che quand arrivano ad un server che ha livello di protezione alto me le vede come spam.

La mail consiste in un oggetto, in un messaggio e in un allegato pdf.

queste sono le intestazioni di una mail vista come spam...

A:
"XXXXXX" <XXXXX@tin.it>
Return-Path:
<XXX@XXXX.org>
Original-Recipient:
rfc822;XXXXX@tin.it
Received:
from vsmtp17.tin.it (192.168.70.176) by ims9c.cp.tin.it (8.0.022) id 49975582000FD5E1 for XXXXX@tin.it; Fri, 20 Feb 2009 16:20:38 +0100
Received:
from mail2.XXXXX.org (89.96.191.109) by vsmtp17.tin.it (8.0.022) id 499E683F00140871 for XXXXX@tin.it; Fri, 20 Feb 2009 16:20:38 +0100
Received:
from mail.XXXX.org (unknown [10.251.1.111]) by mail2.XXXXX.org (Postfix) with ESMTP id E0F46E19A0 for <XXXXX@tin.it>; Fri, 20 Feb 2009 16:20:35 +0100 (CET)
Received:
from hnmail1.XXX.local (unknown [10.38.100.111]) by mail.XXXX.org (Postfix) with ESMTP id ACC05397A8 for <XXXXX@tin.it>; Fri, 20 Feb 2009 16:20:32 +0100 (CET)
Received:
from HXXXX002 (hXXXX002.XXX.local [10.1.185.142]) by hXXX.XXXX.local (Postfix) with SMTP id 93622A6B72 for <XXXX@tin.it>; Fri, 20 Feb 2009 16:20:32 +0100 (CET)
ID-Messaggio:
<000001c9936e$c5767450$8eb9010a@XX.local>
X-MimeOLE:
Produced By Microsoft MimeOLE V6.00.2900.3350
X-Virus-Scanned:
ClamAV 0.93/7030/Mon May 5 06:02:10 2008 on hXXX.XXX.local
X-Virus-Scanned:
ClamAV 0.92.1/9016/Fri Feb 20 05:03:22 2009 on mail.XXXX.org
X-Spam-Flag:
YES
X-Spam-Status:
Yes, score=7.8 required=5.0 tests=AWL,BAYES_50, DNS_FROM_RFC_POST,MSGID_DOLLARS,OBSCURED_EMAIL,RAT WARE_OUTLOOK_NONAME, UNPARSEABLE_RELAY,UPPERCASE_50_75 autolearn=no version=3.1.9
X-Spam-Report:
* 0.0 UNPARSEABLE_RELAY Informational: message has unparseable relay lines * 2.1 OBSCURED_EMAIL BODY: Message seems to contain rot13ed address * 0.0 BAYES_50 BODY: Bayesian spam probability is 40 to 60% * [score: 0.5000] * 1.7 DNS_FROM_RFC_POST RBL: Envelope sender in * postmaster.rfc-ignorant.org * 1.7 MSGID_DOLLARS Message-Id has pattern used in spam * 0.4 UPPERCASE_50_75 message body is 50-75% uppercase * 2.8 RATWARE_OUTLOOK_NONAME Bulk email fingerprint (Outlook no name) * found * -0.8 AWL AWL: From: address is in the auto white-list
X-Spam-Level:
*******
X-Spam-Checker-Version:
SpamAssassin 3.1.9 (2007-02-13) on mail2.XXXX.org
X-Virus-Scanned:
ClamAV 0.93/7010/Fri May 2 02:09:47 2008 on mail2.XXXX.org
X-Virus-Status:
Clean


scusate le XXXX ma non sono indirizzi miei e quindi...

come posso fare per far vedere la mail non come spam???