[atlas] Email or SMS alert when probe goes offline/online

Hi,

personally i would really like such a feature. And from the responses so far i think the mechanism should account for the different mindset of people hosting a probe. I agree with Daniel that the default should be off and the sensitivity should be configurable (e.g. alert after X time offline):

> 2) Providing a service to the hosts that warns them of downtime etc. This should be configurable of course in terms of who gets alerted and how sensitive the trigger for an alert is; the default shold be "off".

Maybe i can extend a bit on this proposal. E.g. with the possibility to specify an alternate email address (other than for the registration) these alert mails could automatically be filtered. 

Personally i would prefer a mechanism that alerts me as soon as connectivity is lost for more than X minutes, with 1 < X < 10. In case i would get to many of these notifications, i would just go to the webpage and turnoff the notifications. 

Another option that just came to my mind is to send an activity report every month or so. This could then include a fraction of time the probe was up and/or connectivity was present. Maybe with a link to the status webpage. So that people are reminded of the existence of the probe once in a while. (Of course this should again be an opt-in mechanism. I would certainly subscribe.)

best
Fabian