On Sep 03, 2010, at 06:53, Fabrice Vendé wrote:
> if FHdrPriority < smtpPriorityNormal then begin
> FHdrLines.Add('Priority: urgent');
> FHdrLines.Add('X-MSMail-Priority: High');
> end
> else if FHdrPriority = smtpPriorityNormal then begin
> FHdrLines.Add('Priority: Normal');
> FHdrLines.Add('X-MSMail-Priority: Normal');
> end
> else begin
> FHdrLines.Add('Priority: non-urgent');
> FHdrLines.Add('X-MSMail-Priority: Low');
> end;
In scanning messages sent from MS Outlook through an MS Exchange Server, I
noticed that it set the following headers:
...
Importance: high
X-Priority: 1
...
This suggests that those two headers are deprecated. SpamAssassin (as
well as other anti-spam engines) tend to look for these obsolete headers as
markers of e-mail sent by a spamming tool.
The rationalization is that users tend to upgrade eventually to the
latest versions of applications, while spamming tools, being created ad hoc and
seldom maintained consistently, do not react as quickly to changes. Thus it is
reasonable to assume that if a spam tool is designed to mimic Outlook at some
time, whenever those headers are changed by Microsoft, only the tool will
continue using them.
I suggest a better solution would be as follows, which more closes
adheres to conventions. These values have been empirically discovered testing
with Apple Mail, MS Outlook, and Mozilla Thunderbird. They are also described
in various suggested standards. Notice that "Normal Priority" is typically
marked by the absence of any priority marker.
procedure TCustomSmtpClient.Data;
...
if FHdrPriority < smtpPriorityNormal then begin
FHdrLines.Add('Importance: high');
FHdrLines.Add('X-Priority: 1');
end
{
else if FHdrPriority = smtpPriorityNormal then begin
FHdrLines.Add('Importance: normal');
FHdrLines.Add('X-Priority: 3');
end
}
else begin
FHdrLines.Add('Importance: low');
FHdrLines.Add('X-Priority: 5');
end;
...
dZ.
--
DZ-Jay [TeamICS]
http://www.overbyte.be/eng/overbyte/teamics.html
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