I just finished it and it's working great so far with the community driver - I just need to put it in the mailbox and see if it works there too. The antenna seems to make a difference already, last time I had to sit it next to the Hub to pair it, this time it paired from a couple of metres away without issues.
and finished:
and now installed in the mailbox - I guess we'll see if it works soon enough. 
I have it facing the back of the mailbox because I don't want it to detect people walking past on the footpath immediately in front of the mailbox. I'm also more interested in knowing when small parcels are delivered.
I prolly should have made the antenna come out the short side, but if it works I can easily modify it.
Installing it into the mailbox immediately didn't work, so I've put it near the closest Zigbee repeater for a while and will try again tomorrow when it figured out its place in the mesh.
The metal is a highly effective faraday cage, which is why I suggested the pcb antenna which can be relocated outside the mailbox. Maybe as a test try mounting it on the outside? Are you able to check LQI?
What’s that?
It’s only the front and rear of the box that is metal, the rest of the box is brick.
Link Quality Indicator, a measure of the quality of the signal. Not sure if we can get this metric from the hub as I've always used an xbee and XTCU software to map my mesh.
Does it work when you mount it on outside the mailbox ?
Hmm I might see if it’s visible in the Zigbee toolbox.
No it doesn’t - I think the antenna is the issue. I’ll try a different one tomorrow.
You can check using the Zigbee logs.
...lastHopLqi:255, lastHopRssi:-49
i.e. http://YOURHUBIPHERE/hub/zigbeeLogs
Cheers, I’ll try that.
Is there an explanation of what the stats mean?
If you click on the "Documentation" link at the bottom of the page it gives a pretty good summary.
https://docs.hubitat.com/index.php?title=Zigbee_Logs
And then just lots of searching the forums. 
Edit: THIS is a fun read, no extra credit. 
And also THIS page turner.
So this one will work up up until it gets halfway from the house to the mailbox - I've ordered a couple of PCB antennas to try (3DBi and 8DBi).
Nice, I havent had that much fun since I read the z-wave command class structure document! 
Cheers, I'll look into the best install options once I can get a useable signal from the mailbox.
It's a shame no one has been able to implement a power-loss option into zigbee bulb drivers. I had to put my 2 Hue bedroom lamps back onto my Hue Hub as they turn on when power is restored which is far from ideal at 2am after a power glitch. The Hue hub is able to prevent this.
Just wanting to point out that they're "Currently in BETA only!"
Whilst the Oh-laLabs team are cranking out awesome product, some users may not appreciate being on the "Bleeding edge". 
Maybe you can adopt something from HERE
I looked at a few different options discussed here in the community, but none where as simple and reliable (or as fast) as just keeping these 2 bulbs on my Hue Hub.
