2.2.5 Mail App Custom Properties

Mail app–specific custom properties on a Message object are stored as a JSON object in a string named property on the Message object. The property is defined as follows.

Property set: PS_PUBLIC_STRINGS {00020329-0000-0000-C000-000000000046}

Property name: cecp-<ID>

Data type: PtypString, 0x001F ([MS-OXCDATA] section 2.11.1)

The <ID> portion of the property name is replaced by a value derived from the value of the Id child element of the OfficeApp element that represents the mail add-in in the mail add-in manifest, as specified in [MS-OWEMXML]. The value is derived by using the following procedure:

  1. Replace any uppercase alphabetic characters in the value of the Id element with their lowercase equivalent. For example, 'A' becomes 'a'.

  2. Remove any braces ('{' or '}') from the value.

  3. If present, remove the "urn:uuid" prefix from the value.

The value of the property is a JSON object that contains name-value pairs, where the name is the name of the custom property and the value is the value of the custom property. The value is limited to a maximum of 2,500 characters.