bouncing mails doesn't work

[Vincent Lefevre]

On one of my accounts, bouncing mails work, but not on the other, though
Mutt said the message has been sent. :(

On both accounts, sendmail is used. And sending a normal mail works
as expected. Where's the problem?

-- 
Vincent Lefèvre <[EMAIL PROTECTED]> - Web: <http://www.vinc17.org/> - 100%
validated HTML - Acorn Risc PC, Yellow Pig 17, Championnat International des
Jeux Mathématiques et Logiques, TETRHEX, etc.
Work: CR INRIA - computer arithmetic / SPACES project at LORIA