If you have a Gmail account, firstname.lastname@example.org, Google allows you to use an alias like email@example.com and still redirect all emails to root email. (Notice the
I just signed up on WorkPlace site with firstname.lastname@example.org but for some reason the confirmation e-mail came from stackexchange instead and, not surprisingly, I cannot login using those credentials on Workplace. Upon login it tells me that ”The email or password is incorrect”.
So, even if I initiated the signup on that site, it ended up to sign me up on this site instead.