mail.local / mail

From me

>From me

Do you see the two above lines as identical?

mail.local quotes only the first line above with ">".
"mail" does not delete it. See:

https://man.openbsd.org/mail.local

Many years ago I used "mail" a lot with the old SunOS (BSD derivative).
I remember it used MMDF, I remember clearly the ^A^A^A^A separators,
I remember that I used a "mail" program that behaved like the BSD one,
but I do not remember any problem writing "From" at the beginning
of a paragraph following an empty line.

Rodrigo