Re: mails get flagged in OutLook

--NzCgoAIsXgcjw3Px
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

<On Sat, Feb 14, 2026 at 06:15:26PM +0000, Nuno Silva via Mutt-users wrote:>

> On 2026-02-09, Matthias Apitz wrote:
>=20
> > Hello,
> >
> > I'm adding to all my mails sent with mutt (like this one) two X-header
> > lines:
> >
> >     X-Operating-System: FreeBSD 14.0-CURRENT r1400094 (amd64)
> >     X-message-flag: Mails in HTML will not be read! Please, only plain =
text.
> >
> > I got informed by an reader of a mailing-list that my mails get flagged
> > in his OutLook mailbox with a small red flag. Technically this is added
> > by a Microsoft SPAM protection which adds into my mail a header among o=
ther
> > stuff a line like this:
> >
> > ```
> >     X-Microsoft-Antispam-Mailbox-Delivery:
> > 	ucf:0;jmr:0;auth:0;dest:I;ENG:(910005)(944506478)(944626604)(4710137)(=
4713098)(499
> > 9163)(920097)(930201)(20251009147)(140003);
> > ```
> >
> > I did tests with an OutLook destination I've access to and the "culprit"
> > seems to be only this X-header:
> >
> >     X-message-flag: Mails in HTML will not be read! Please, only plain =
text.
> >
> > Any comments on what could he do or what could I do?
> >
> > Thanks
> >
> > 	matthias
>=20
> Are you sure the red flag is related to spam/junk detection and isn't
> just Outlook's way of showing that a message has been "flagged", with
> the presence of the header being regarded as a flag too?
>=20
> I just tested with a Microsoft-hosted account here, and
>=20
> 1) I can confirm the flag text still shows up, above the message, in the
>    current version of Outlook webmail (the blue envelope one).
>=20
> 2) Messages with X-Message-Flag get that red flag set. Tooltip over it
>    says "Unflag this message", and when displaying the message, it also
>    gets a red flag between headers and body, followed by the red text
>    "Flagged".
>=20
> 3) Both test messages arrived in the Inbox, not "Junk Email".
>=20
> --=20
> Nuno Silva

A far as I remeber this is just an annoyer for Outlook users.
I have this on my .muttrc since 20+ years.=20

# Outlook Annoyer: Flags and tags each email fairly obviously
my_hdr  X-Message-Flag: Cranky? Try Free Software instead!

It is funny that it is still working.
I was used to be asked by outlook users why all my emails are flagged
with a small red flag... But this has nothing to do with a spam tag.
Best,
Nicola
=20

=20

--NzCgoAIsXgcjw3Px
Content-Type: application/x-pkcs7-signature
Content-Disposition: attachment; filename="smime.p7s"
Content-Transfer-Encoding: base64
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--NzCgoAIsXgcjw3Px--