How I get notified every time their is an *new* update and not every day for the sames updates? The update module can send you email when a new release is available for a module you installed. The problem is I get a email everyday. Some security update are very minor and unreachable for an attacker, I don't want to update the website and so I don't want future notification about this update.

I would like to be notified every time their is an new update, not every day for the sames updates.
I can use hook_mail_alter to cancel the sending of the mail. I can simply store a md5 of the mail's body every time the mail is send and compare it with the "new" email, if it's the same I don't send it.