The emails are still there. The link seems to have changed. Here’s the link just derived: http://jebbushemails.com/email/results/20050331
If that doesn’t take You to that day just click on the calendars below and go to March 31, 2005.
Seems they have somehow fiddled with the indexing. That link you posted is date specific - the numbers at the end is year / month . date. But it links to the main page.
Yesterday, I shared a link with a woman whose cell number was in her email and then, that link went directly to the specific email. Not the case now, but the email (with cell number) can still be found using the calendar.