A) A friend got bit badly by the "anything I can attach I will"
syndrome. He was in the UK, and the usual USG local POP (from PSI)
was FUBAR.

So he called back to DC to get urgent mail. Some MITRE genius
had attacked a 10+meg PowerPointless file to his message to 100+
folks, including Friend. Friend err (rather you & I) paid a VERY
large phone bill for that braindeadness.

B) I'm intrigued by the proposal for pseudo attachments.
Hmm, what's really needed?

  1) User still points & clicks.
  2) MUA uploads attachment to its designated server.
  3) MUA attaches URL & password to message.
  4) Recipient gets mail and grabs attachment.
  5) Server knows who has gotten file, keeps track.
  6) 24 hours after last recipient has claimed it, or {say}
  1 week later, it deletes it. Replaces with "it's expired,
  have it resent" for whenever. (Gee, this sounds like news
  and history files...)

All this needs to work is for say Eudora and Mutt to both offer it.
Once a critical mass of sysadms deploy same, and crank down the
limit to 100K, more will. (I say Eudora because M$ will resist
anything that interoperates....)