NewEmailAddressValidator takes in a list of email addresses and returns a Validator object.

NewEmailDomainValidator takes in a list of domains and returns a Validator object.

NewEmailGroupValidator takes in a Provider object and a list of groups, and returns a Validator object.

RunValidators runs each passed in validator and returns a slice of errors.

These error message should be formatted in such a way that is appropriate for display to the end user.

These error message should be formatted in such a way that is appropriate for display to the end user.

These error message should be formatted in such a way that is appropriate for display to the end user.

These error message should be formatted in such a way that is appropriate for display to the end user.