smtplib & Bcc

[Robin Becker]

A colleague and I are wondering if smtplib does anything special about
the Bcc header, or perhaps the truth how we should use the Bcc header.

I tried some simple experiments with Bcc: and cc: inside the message and
it seems, when I send these using smtplib, that the cc list gets sent
to, but the Bcc list receives no copy of the mail. Can some kind soul
explain how we should use the Bcc header?
-- 
Robin Becker