On Mon, Feb 16, 2026 at 10:01:07PM +1100, raf via Mutt-users wrote: > On Mon, Feb 16, 2026 at 08:28:44AM +0100, Nicola Pinna > <[email protected]> wrote: > > > <On Sat, Feb 14, 2026 at 06:15:26PM +0000, Nuno Silva via Mutt-users wrote:> > > > > > On 2026-02-09, Matthias Apitz wrote: > > > > > > > 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 > > Hi, > > I expect that it's unlikely that recipients of your > emails would see the X-message-flag header. I might be > wrong, but many non-mutt mail clients I see don't show > many headers at all (not even the From: header!). You > have to out of your way to see them. > > It probably makes more sense to remove that header, and > add your plea to your signature. That way, recipients > can actually see it without additional/unlikely effort > on their part. > > However, if you want to accept that other people will > continue to do what they do, and you have no control > over that, I have a program that might help you > (raf.org/textmail). It converts HTML emails to plain > text, and Excel attachments to CSV, and Word/PDF > attachments to text, delete images, etc. If your email > is delivered in a way that you can use procmail to > filter it before it's saved, you could convert incoming > emails to plain text before you see it. > > cheers, > raf >
Question here is whether you are going to adapt to some quirk in MS Outlook, or just use mutt the way it is designed. There are a lot of things where Microsoft software interpretes and displays things differently from non-MS software. IMHO we shouldn't bow for that, nor its users. //meine
