On 2026-02-16, 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: >> > >> > > 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 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.
As has been stated a few times: recipients using at least some Microsoft MUAs *will* see the content of that header in the user interface. It's not shown as a header, it's shown as a sort of label on the message. > 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. If this is only visible in Microsoft MUAs, it makes sense that it'd be used if users of such MUAs are the target group for the message, or at least a significant part of the target group. Say, Microsoft MUAs used to be the main source of badly formatted e-mails (even plain text ones), top-posted and without citation indicators. These days, it seems that's not so much the case (this in the being "the main source" part), but mainly because some client software and also some webmails have opted by duplicating Microsoft's approach to e-mail. Not to mention non-text non-HTML formats in e-mail (didn't MS at some point use RTF or the like for formatted e-mails?). > 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). There is value in telling people that their MUA is doing something, if they aren't aware of it. With people using Microsoft software, it can often be the case they're not aware there's a whole world outside of Microsoft. > 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. -- Nuno Silva
