# File lib/mail/field.rb, line 68
    def initialize(name, value = nil)
      case
      when name =~ /:/ && value.blank?   # Field.new("field-name: field data")
        name, value = split(name)
        create_field(name, value)
      when name !~ /:/ && value.blank?  # Field.new("field-name")
        create_field(name, nil)
      else                              # Field.new("field-name", "value")
        create_field(name, value)
      end
      return self
    end