I was having network problems with a site connected via VPN so I decided to turn on the email option so that I would know when phones changed their registration status. This worked well, to know when this site went down, but what I discovered is that all of my other phones were constantly un-registering and re-registering all throughout the day. Most of the phones are T22's running 184.108.40.206, but there are a handfull of higher models. From what I can tell there doesn't seem to be any negative affect on the operation. I don't know if it is just happening so fast that no one happens to be dialing at that time. I would suspect there may be a handful of call failures and maybe they are just not being reported. Anyway, I would assume this is a reg timer issue or something? All of the phones are configured via the provided provisioning files. Assuming this is the normal operation for the Yealinks it pretty much renders this alert feature useless. It is around a 100 phone installation, so my inbox is getting a workout since I have enabled this! Just for my own curiosity I turned this on at some other sites that don't use Yealink and I have one or two emails in a week where this happened which seems more reasonable.