I've nailed it! It can be done!!! I've now done it and tested it!
I had so many request over the years to be able to block certain incoming calls based on their caller ID that I can't count them.
I see a request for this at least once a month.
Now I've found a way to do it. No additional hardware/software needed.
I'm working on a How-To now. When it's done I'll publish it on line here in the forum.
This is some pretty hard core techie stuff. Just yesterday I spoke with a senior Mitel Tech Support engineer that said it couldn't be done.
It can be. It's not that easy to set up but once it is set up then it's really easy to block numbers.
It took me several hours of lab work, debug and testing so once I put the How-To out there, if you use it, ya'll need to buy me a beer.
Ralph