It happens if the email doesn't exist
doesthus the mail bounces and
renamerenamed your email to
something like that.
Check this reply when theymos mentioned it
, probably it was implemented not so long ago from that date reply.
This is something we recently started doing. If email sent to your email address bounces with an error message like, "This email address doesn't exist", then your email may eventually be changed to u...@bounces.invalid. (It's not possible for users to change their email address to something ending in .invalid, so this can only be an administrative change.) Because your old email didn't exist, somebody could've registered your non-existent email address and used that to steal your account.