#11555: update doc for 3.x change to as_string mangle_from default.
diff --git a/Doc/library/email.message.rst b/Doc/library/email.message.rst
index f261b9c..d1a12c5 100644
--- a/Doc/library/email.message.rst
+++ b/Doc/library/email.message.rst
@@ -46,15 +46,16 @@
be generated or modified).
Note that this method is provided as a convenience and may not always
- format the message the way you want. For example, by default it mangles
- lines that begin with ``From``. For more flexibility, instantiate a
+ format the message the way you want. For example, by default it does
+ not do the mangling of lines that begin with ``From`` that is
+ required by the unix mbox format. For more flexibility, instantiate a
:class:`~email.generator.Generator` instance and use its :meth:`flatten`
method directly. For example::
from io import StringIO
from email.generator import Generator
fp = StringIO()
- g = Generator(fp, mangle_from_=False, maxheaderlen=60)
+ g = Generator(fp, mangle_from_=True, maxheaderlen=60)
g.flatten(msg)
text = fp.getvalue()