CakeMail v4 is currently down. We are investigating the issue. Updates will be posted here.
update@3:15pm : The tracking links are affected. We expect a back to normal within 30 minutes.
update@3:47pm : We are still investigating the problem.
update@4:00pm : Tracking links should back to normal in about 15 minutes.
update@4:20pm : Situation is back to normal.