I have gotten thrown into trying to solve a troublesome issue with our Starplus STS system.

We have the voice mail tree set up so that when the phone is unanswered they hear the welcome followed by "press 1 for....press 2 for...and so on.
Here is the problem...
Sometimes when someone calls and it goes unanswered, it works correctly. i.e. it goes to the voice mail system correctly.
Sometimes when a call goes unanswered instead of going to the voice mail tree it goes to a certain extension and gets that specific person's voice mail (not the voice mail tree). I can not figure out why it is doing that.

I have a "Station User Guide" and have tried clearing out every bit of call forwarding and I even thought that maybe the station it is going to was set up as a Secretary Station but I have no idea how to change that if it is.

We have three lines and it's all set up to "hunt" for those other two lines if line 1 is busy. But this issues happens regardless if there is a call on line 1 or not. I have contacted a local Vodavi company here and they have no idea what to do. And of course when their tech is here and calls in the voice mail system works exactly as it's supposed to.

Any ideas?

Sounds like there is a preset forwarding condition on a line and if the voice mail is busy it comes into play and rings to a station that is preset forwarded to voice mail. Preset forwarding is not a user set function...it is done in admin. You may need a tech to figure this one out for you.

Great. The company that installed this system is no longer in business and Vodavi gave me a number of a local company that they have and it's not in service either. I have another local company working on it but
1-they cannot recreate the problem (when their guys call the voice mail works just like it should)
2-they are not an official Vodavi dealer so they are guessing as well.
But the good news is that they are not giving up. But we are getting very frustrated.

Thanks for the help though.

It sounds like you might have 1 or more lines programmed differently than the main number. Maybe you or your vendor should call in directly to each line on the system and see if they all follow proper routing. If you find 1 or more lines routing improperly, then simply change the preset fwd destination for that line.

Could there possibly be an automatic schedule on the phone system? Maybe in the evening the calls are forwarded directly to a personal mailbox and the time on the voice mail system doesn't match the time on the phone system, thus causing a forwarding issue.

Besides trying every incoming CO line, you might want to individually dial each voice mail port and see if you receive the company's main greeting and menu tree.

I think Jim is on to something. And his 2nd sentence is important. Do both of those tests before you invest your time on other areas.