From the blog "Featured News"

There are lots of things in Second Life that send email, but as many of you have discovered, that email doesn't always get to the intended recipient. There are a lot of reasons for email from SL not being as reliable as we'd all like, and the Lab is working on fixing as many of those as we can, but some of them need your help. One of the most important reasons mail doesn't get through is that many Second Life accounts have bad email addresses - when something in Second Life sends to one of