Not that I know of. I don't know why anyone would need such a warning. You can't have a warning for everything, it will just piss people off.

Just pay attention to what you are doing.

Waw Bruce, that's probably the most handy answer I have ever read in my life, thanks for that ! (y) No wonder you're in the Top 25 with such awesome answers.

(and now in "sarcasm mode: off": you also get a warning when you forget to add attachment because of particular keywords written in an email, so something similar to this for bcc would be very useful. And it's very easy to implement (code wise) and if (as in your reply) this warning "will just piss people off" you turn it off.)

I don't think I have understood the nature of the query.

You're bothered about Bcc'ing yourself? Why?

Person A sends an email to person B, C & D , and I'm (let's say person E) in this email in BCC. I don't pay attention that I'm in BCC and I hit the "reply all" button and so the email is sent from me (person E) to A, B, C & D, this way persons B, C & D see that I was in BCC in the first email and person A is screwed.

Listen up Smirnoff103. As you say, you are not paying attention. So put down your vodka and pay attention to what you are doing!

You are screwing up, and want an e-mail program that will hold your hand and warn you that you are screwing up. If there is an e-mail program out there that does this, then I will be surprised.

(the first hit on google) I present you the most used mail client in the world, with (almost) a warning of bcc https://www.msoutlook.info/question/you-may-have-been-bcced-warning

)

And somebody already asked about it for Thunderbird, only 14 years ago, a true visionary !! https://bugzilla.mozilla.org/show_bug.cgi?id=209337

Smirnoff103 said

And somebody already asked about it for Thunderbird, only 14 years ago, a true visionary !! https://bugzilla.mozilla.org/show_bug.cgi?id=209337

Feel free to comment on that bug and try to revive it. Or create a new bug if you want.

For your purposes, a work around would be to create a message filter that detects incoming messages that don't have your e-mail address in the To or CC, and put them in a particular folder. See screenshot.

So you see Bruce if you want that you can ;) For me your last reply was good enough to be marked as a "solution", it's not exactly what I wanted but I created a "bcc tag" with a black colour and this is marked now automatically in black, I had a few mails in bcc yesterday & today and I immediately saw it. Thanks for your time.