TL;DR: Blacraft will be down sometime on September 30, and afterwards the new IP will be 85.236.109.242:2137.
Copy from an email:
Multiplay Gameservers - Important information!
Hi Mikkel,
Multiplay Gameservers are committed to providing the very best and latest network equipment with which to run our servers on. We very rarely have to upgrade this hardware, however to continue giving you the best experience possible, we have to implement upgrades periodically.
We are currently carrying out a large number of upgrades to our network in order to greatly improve the stability of the service we provide and we are emailing you today to let you know that we will be making some changes to your service next week as part of these upgrades.
We have scheduled this outage on:
Monday 30th September 2013 for approximately 60 minutes between the hours of:
9am (GMT +1) and 6pm (GMT+1)
Unfortunately part of the changes we're making require the IP address of your server to change and whilst we try to prevent this where possible, we haven't been able to on this occasion. We are however able to provide the new IP address that your server will be moving to. This will be: 85.236.109.242:2137
Please accept our apologies for any inconvenience this may cause you. We have not taken this decision lightly and believe this upgrade will provide great improvements with the quality of servers we provide.
If you have any questions please contact our Support Team and we will be glad to help.
The MultiplayGameservers.com Team.