mails get flagged in OutLook

[Matthias Apitz]

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 other
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

-- 
Matthias Apitz, ✉ g...@unixarea.de, http://www.unixarea.de/ +49-176-38902045
Public GnuPG key: http://www.unixarea.de/key.pub

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