```ruby
module Authlogic
  # This is a module the contains regular expressions used throughout Authlogic. The point of extracting
  # them out into their own module is to make them easily available to you for other uses. Ex:
  #
  #   validates_format_of :my_email_field, :with => Authlogic::Regex.email
  module Regex
    # A general email regular expression. It allows top level domains (TLD) to be from 2 - 4 in length, any
    # TLD longer than that must be manually specified. The decisions behind this regular expression were made
    # by reading this website: http://www.regular-expressions.info/email.html, which is an excellent resource
    # for regular expressions.
    def self.email
      return @email_regex if @email_regex
      email_name_regex  = '[A-Z0-9\.%\+\-]+'
      domain_head_regex = '(?:[A-Z0-9\-]+\.)+'
      domain_tld_regex  = '(?:[A-Z]{2,4}|museum|travel)'
      @email_regex = /\A#{email_name_regex}@#{domain_head_regex}#{domain_tld_regex}\z/i
    end
    
    # A simple regular expression that only allows for letters, numbers, spaces, and .-_@. Just a standard login / username
    # regular expression.
    def self.login
      /\A\w[\w\.+-_@ ]+\z/
    end
  end
end```

Add _ as allowed character in email, fixes change made last night
user
```ruby
module Authlogic
  # This is a module the contains regular expressions used throughout Authlogic. The point of extracting
  # them out into their own module is to make them easily available to you for other uses. Ex:
  #
  #   validates_format_of :my_email_field, :with => Authlogic::Regex.email
  module Regex
    # A general email regular expression. It allows top level domains (TLD) to be from 2 - 4 in length, any
    # TLD longer than that must be manually specified. The decisions behind this regular expression were made
    # by reading this website: http://www.regular-expressions.info/email.html, which is an excellent resource
    # for regular expressions.
    def self.email
      return @email_regex if @email_regex
      email_name_regex  = '[A-Z0-9_\.%\+\-]+'
      domain_head_regex = '(?:[A-Z0-9\-]+\.)+'
      domain_tld_regex  = '(?:[A-Z]{2,4}|museum|travel)'
      @email_regex = /\A#{email_name_regex}@#{domain_head_regex}#{domain_tld_regex}\z/i
    end
    
    # A simple regular expression that only allows for letters, numbers, spaces, and .-_@. Just a standard login / username
    # regular expression.
    def self.login
      /\A\w[\w\.+-_@ ]+\z/
    end
  end
end```
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