When I exit the mail command after having looked at a mail message, I get this message: Segmentation fault (core dumped) The mail messages that were read remain in the mail box and are not stored in the $HOME/mbox. I assume the problem comes when it tries to write to the mbox. It exits without a problem when I don't look at any messages.
This defect is considered SHOULD-FIX for Winston Gold release
Works for me in post-RC1.