When you send a email message just add your dropbox email address to the BCC address field.  I think you could also create a rule in MacMail for this to happen automatically.

Does anyone out there know how to automatically do this in Macmail Rules?

Not tested…

http://www.hawkwings.net/2007/01/28/adding-a-default-reply-to-address-in-mailapp/

http://pluckytree.org/downloads/applescripts.zip

Thanks for the tip.  It works great!  One issue still of concern is, regardless of inbound or outbound messages, it appears all email correspondence is duplicated.  Also, will we be able to trash individual emails?

>> regardless of inbound or outbound messages, it appears all email correspondence ...

Ultimately it is up to each user/customer how they prefer to manage their email messages.  If you set everything to “auto” it will create a bit of noise.  The email dropbox is intended to be an effective way to share correspondence across a team / create a profile for a specific contact / project blog.

Dropbox Reply and Forward message functions will be enabled when the webmail feature is available.  At that time, if you are saving messages to the dropbox there is little need to keep a copy in your personal email account.