Mail user has two object classes: inetOrgPerson, mailUser.
As defined in , mail user has 'displayName' attribute:
objectclass ( 2.16.840.1.113730.3.2.2
NAME 'inetOrgPerson'
DESC 'RFC2798: Internet Organizational Person'
SUP organizationalPerson
STRUCTURAL
MAY (
audio $ businessCategory $ carLicense $ departmentNumber $
displayName $ employeeNumber $ employeeType $ givenName $
homePhone $ homePostalAddress $ initials $ jpegPhoto $
labeledURI $ mail $ manager $ mobile $ o $ pager $
photo $ roomNumber $ secretary $ uid $ userCertificate $
x500uniqueIdentifier $ preferredLanguage $
userSMIMECertificate $ userPKCS12 )
)
As defined in iredmail.schema, mail user has 'telephoneNumber' attribute:
objectclass ( 1.3.6.1.4.1.32349.1.2.4.3 NAME 'mailUser'
DESC 'Mail User' SUP top AUXILIARY
MUST ( mail $ uid )
MAY ( storageBaseDirectory $ mailMessageStore $ homeDirectory $
userPassword $ mailHost $ mailUID $ mailGID $
mailQuota $ mailQuotaMessageLimit $
mailForwardingAddress $ accountStatus $
userRecipientBccAddress $ userSenderBccAddress $
enabledService $ telephoneNumber $ backupMailAddress $
mtaTransport $ memberOfGroup ))