Try powering off the Elite phone system, wait 5 minutes, then slide the make busy switch down. Pull the Elitemail card from it's slot & re-seat it. Wait 5 more minutes, then slide the make busy switch back up. Wait 5 more minutes, then power up the Elite phone system.
Does the Elitemail have a "hardrive"? If so, does it make abnormal "squeeling, whining, or "clanking" noises? If so, your drive may be shot.
FYI...the CPU battery on the Elite series, or any phone system, needs to be replaced every 2-3 years. I have seen the battery last for almost 5 years, however, you may lose your Elite's database when you power off the KSU.
If the Elitemail boots up with led's 1-4 lit red then hangs...you may be able to connect with cosessions & resolve any database errors.
Good luck!