2.2.1.36 PidTagAlternateRecipientAllowed Property
Type: PtypBoolean ([MS-OXCDATA] section 2.11.1)
The PidTagAlternateRecipientAllowed property ([MS-OXPROPS] section 2.577) specifies whether the sender permits the message to be autoforwarded. This property is set to "TRUE" if autoforwarding is allowed.