FTP
FTPmail is really just internet mail where specially formatted
messages are sent to a robot requesting some limited FTP
interactions. The results are bundled in to a series of byte(uh,
bite)-sized pieces, 60k or so each. The bundles are numbered and
mailed individually. You retrieve them and paste them back together
and decode them using atob, uudecode or whatever.
I've used FTPmail frequently in the past. You only have to know the
address of the robot, and have a mailbox big enough to handle the
stuff you get. A full GCC archive is several *mega*bytes of mail(!)
I haven't done this from CI$ though.