There's a couple of different platforms that have been called the 5000 over the years, so you may be getting those confused. The first Mitel 5000 started out as the Inter-Tel 5000, and is now known as the MiVoice Office 250. It was re-named after Mitel acquired Aastra, who was selling the plaform now known as the MiVoice 5000 in Europe. I'm not familiar with that platform at all, but what is now the MiVoice Office 250 is end-of-sale, and the latest release on that platform is 6.3 SP7. If that's what you have, I would start planning on replacing it as it is end of sale, and will be going out of support soon.