OT: Outlook oddities

Glenn Steen glenn.steen at gmail.com
Mon Mar 8 16:42:06 GMT 2010

On 8 March 2010 15:53, Steve Campbell <campbell at cnpapers.com> wrote:
> Just wondering if anyone ever experiences email sent by Outlook senders that
> have no "From" in the envelop? The headers seem to have the proper "From"
> entry. These get caught quite often by MS (actually SA) with a "no watermark
> or sender address". They are sent from our users, which normally get
> whitelisted by IP address. The problem doesn't always happen even from the
> same sender.
> Thanks and sorry for the OT
> Steve Campbell
The empty sender (MAIL FROM:<>) is a valid sender reserved for the
mail system itself. Typically used for delivery reports (or rather
"non-delivery":-). Since all mail coming into your system having an
empty sender need be in response to a mail sent from you, MailScanner
(not SA) adds a watermark header... The "returning MTA" is supposed to
preserve that in the reply/DSN/NDN, so MailScanner checks for that and
stamps any mail lacking a watermark, or having a forged one, as spam.

So you need look a bit harder on from where you get these, and in what
situations;-). It's probably doing just the thing it should:-);-)

-- Glenn
email: glenn < dot > steen < at > gmail < dot > com
work: glenn < dot > steen < at > ap1 < dot > se

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