"When an email is sent to a BlackBerry user, it is first picked
up by a BES server, pre-processed/distilled/put on slim-fast/etc.
and then sent to the device. The net effect is that the recipient
just gets the "raw text" of the message and a list of attachments
which are individually download-able.
"When an email is forwarded from a BlackBerry user, the BES
magically sends the original email — complete with the
attachments and any text added by the mobile user. Contrast that
behavior with an Android user attempting the same "comment and
forward" activity — it just isn't the same.
"The other day I read a message on my Android device but didn't
download the attachment. Then I forwarded it to someone on my team,
making reference to the attachment. They shot back a note saying
"what attachment?". Unfortunately, the attachment was never sent
because it wasn't first downloaded to my phone."