Beware of emails pretending to be from YouTube. I’ve received a few variations notifying me that my video has been approved or that I’ve received a personal message. It includes a link to your new video or a link to what looks like your inbox but it is in fact a third party website.
The thing that raised alarm bells in my mind was that it was sent to one of my email addresses that doesn’t have a YouTube account associated with it.
The easiest way to tell if emails like these are authentic is to hover your cursor over a link in the email and look at the address that pops up. Eg: hovering over what looked like a link to my inbox was in fact a masked link to the spammer’s own website.
As a general rule, you should never click on URLs in emails from anyone other than your trusted friends.