(mail-extr-delete-char, mail-extr-safe-move-sexp)

(mail-extr-delete-char, mail-extr-safe-move-sexp)
(mail-extr-skip-whitespace-forward, mail-extr-nuke-char-at)
(mail-extr-skip-whitespace-backward, mail-extr-undo-backslash-quoting):
Use `defsubst' rather than a macro to ease debugging.
(mail-extr-last): Remove (use `last' instead).
(mail-extract-address-components): Properly reset the syntax-table
after parsing an address.  Use `last' rather than mail-extr-last.
Make sure the end marker stays at the very end.