Number of values
The person's public email address used to contact the person regarding matters related to their organisation.

A valid email address as defined in RFC 822.

Notes on usage
Mail address should only be used when the service provider needs to communicate with the end user. It should not be used as an identifier and should not be relied upon to be persistent.

Notes on privacy
This attribute should not be used in transactions where it is desirable to maintain user anonymity. Privacy considerations should be observed when making a decision about releasing this attribute, as it provides user contact information.