By storing these custom MAPI roles in the ACL.
The extension field 'X-SOGO-COMPONENT-CREATED-BY' is used to store the
event creator when it is done from Outlook. It is the same field SOGo
uses when an event is created from a shared folder in the webmail.
The creator and the organizer/owner of the event can be different and it can
be used from external sources by checking the organizer field. This matches
the specification from [MS-OXOCAL] Section 1.1 which defines the organizer
as the owner or creator of the event.
This specifies a little the scope of the variable to make it
more realistic with the actual values it may have. We do have
a static typed compiled language, why don't we use it?
If the event was created by the MAPI client, the client's time zone (if
present) is assigned to the event's calendar in iCalEvent+MAPIStore.
This way, we can use it to deliver the event's properties correctly.