have they properly sorted out the security issues/account problems now ?
Open a ticket to unblock port 25. I got a response within an hour saying that port 25 is unblocked and they've sent me a link for some anti-spam policy. https://www.vultr.com/legal/antispam_policy.php. No other questions asked. You have to pay $5 per each spam email you send, but if your server was hacked, you are not responsible.