Link: user67@example.com.
Blockquoted: user67@example.com
Auto-links should not occur here: <user67@example.com>
or here: <user67@example.com>
And with the mailto bit:
Link: user67@example.com.
Blockquoted: user67@example.com
Auto-links should not occur here: <mailto:user67@example.com>
or here: <mailto:user67@example.com>