R. David Murray added the comment:
This is a long-standing design choice in the email package. If you want to
advocate for changing it, please join the email-sig mailing list (see
mail.python.org). We are in the process of developing a new version, which
will at least reject things like dup
New submission from Toni Mueller :
email's usage of __setitem__ is highly counterintuitive to the point of being
dangerous. The documented behaviour is (quote):
__setitem__(name, val)
Add a header to the message with field name name and value val. The field
is appended to the end of the
