Back at my desk I took a look at the actual code that does this rejection:
Right at the top we’re checking the canonical email against the blocklist:
def self.canonical(email)
name, domain = email.split("@", 2)
name = name.gsub(/\+.*/, "")
name = name.gsub(".", "") if %w[gmail.com googlemail.com].include?(domain.downcase)
"#{name}@#{domain}".downcase
end
And even if that didn’t catch it, it would be caught by the Levenshtein distance check here:
[1] pry(main)> ScreenedEmail.levenshtein('fakezabanshenas@gmail.com', 'fakezabanshenas+1@gmail.com')
=> 2
as the default for SiteSetting.levenshtein_distance_spammer_emails is 2.