Standard for soft return by automatic word and line wrap

[Ralf Mardorf <ralf.mardorf@alice-dsl.net>]

After 72 signs my MUA does an automatic line wrap.
When I receive mails from the list and I do reply, sometimes the quotes
are bad. I experienced the same with mails from a friend and he told me
that it takes 78 signs for him.
Is there a standard for how many signs it should take to do an automatic
line wrap?

I also wonder if there are any light weighted editors able to do no
automatic line wrap for programming and to do automatic line wrap, when
using them for non-program-code-text.

Regards,
Ralf

PS:
12345678-1-2345678-2-2345678-3-2345678-4-2345678-5-2345678-6-2345678-7-2
new line