Several of you have emailed me to let me know of a Firefox and Thunderbird feature that you might not be aware of - both applications phone home on a daily basis.

I found this out a few days after I decided to start using Thunderbird and created strict firewall rules as a precaution.

I noticed that Thunderbird would, for no reason at all, sometimes try to contact a server over SSL. I looked up the ip address 63.245.213.32 and found it belonged to Mozilla.

What this tells Mozilla each day:
- IP address
- What time you were using the product
- What exact version number you were using
- If you are using any of the plugins or addons sent in the disabled list
- Total number of active users of their software

More Here and Here