Description: Adds another email address that the mail will be sent as "carbon copy", in a form like email@example.com
Argument: valid email
</MAIL> not needed for Keymacro file
See Also: <MAIL>, </MAIL>, <MAIL>CC, <MAIL>BCC
A valid email address should
specify the email address that mail will be sent as "BCC", in a
form like firstname.lastname@example.org or -from "Tom Carter
<email@example.com>". The address is added to the "BCC:"
header and to the list of recipients. Can be repeated as many times
as required to build a list of multiple recipients
Must be specified before each
<MAIL>SEND command. <MAIL>SEND clears the buffer of any
previous <MAIL>BCC_ADD entry.