Custom zope.schema fields for email addresses

email_fields.py

class CustomValidationErrorMixin(object):
    """Schema field with a custom validation error message.

    Mix this class with your schema fields and specify
    which exception they should raise by overriding the
    _validation_exception attribute.
    """

    _validation_exception = ConstraintNotSatisfied

    def _validate(self, value):
        try:
            super(CustomValidationErrorMixin, self)._validate(value)
        except ConstraintNotSatisfied:
            raise self._validation_exception, value


class InvalidEmail(ValidationError):
    """This does not look like a valid email address"""


ASCII_EXCEPT_SPACE_AND_AT = r'[\x21-\x3F\x41-\x7E]'


class EmailAddressOnly(CustomValidationErrorMixin, TextLine):
    """A text field for email addresses.

    Accepts only emails (no real name part, no comments, no angle brackets).
    """

    # This is slightly more and slightly less than RFC-2822 allows
    constraint = re.compile(r'^%s+@[^. @]%s*[^\'@ ]$' % (
            ASCII_EXCEPT_SPACE_AND_AT,
            ASCII_EXCEPT_SPACE_AND_AT)).match
    _validation_exception = InvalidEmail


class EmailWithFullName(CustomValidationErrorMixin, TextLine):
    """A text field for RFC-2822 email addresses.

    Accepts "Name <addr@ess>" as well as "addr@ess".
    """

    # allow all printable US-ASCII characters except SPACE
    # this is slightly more and slightly less than RFC-2822 allows
    constraint = re.compile(r'^%s+@%s+$'
                            r'|^.* +<%s+@%s+>'
                            % (ASCII_EXCEPT_SPACE_AND_AT,
                               ASCII_EXCEPT_SPACE_AND_AT,
                               ASCII_EXCEPT_SPACE_AND_AT,
                               ASCII_EXCEPT_SPACE_AND_AT)).match
    _validation_exception = InvalidEmail

The regexps aren't very good; they allow a bunch of invalid email addresses past:

email@example'com
email@example
email@0
email@example$com
email@example/com
email@example..com
email@.example.com
email@example-com