I started on Fidonet a billion years ago so I know how to do interleaved replies in email if I need to, if everyone else in the same discussion is doing it and knows how.
But every so often you come across people that don't know how to do it, yet wants to, and then you get the weirdest solutions like "see my responses in red", and you have to scan the email yourself instead of having it clearly marked by your email software.
But every so often you come across people that don't know how to do it, yet wants to, and then you get the weirdest solutions like "see my responses in red", and you have to scan the email yourself instead of having it clearly marked by your email software.