All-day and recurrent events have a binary property that describes the
time zone they take place in. We were using the user's time zone in
the webmail, but it may not be equal to the one in the client. This
difference eventually leads to time shifts in events.
Outlook sets recipient type of Required attendees as MAPI_TO and
optional ones as MAPI_CC, so the fix is just to not only iterate
over the "to" list of recipients but also the "cc" one. We're
also setting the proper iCal value for this case (OPT-PARTICIPANT
instead of REQ-PARTICIPANT)
In [MS-OXOCAL] Section 2.2.4.10.7 says the recipient type is 0x01
as Required and 0x02 as Optional and other documents such as
[MS-OXCMSG] 2.2.3.1.2 indicates that MAPI_TO is 0x01 and MAPI_CC
is 0x02, that's why is stored in 'to' and 'cc' respectively.
According to [MS-OXICAL] Section 2.1.3.1.1.20.13, the EXDATE property
must be written only if there are ocurrences from the series that have
been deleted and before this commit ModifiedInstanceDates were also
included.
We check against every ExceptionInfo from exception ocurrences of the series
to know if the ocurrence was deleted or only modified.
get_AppointmentRecurrencePattern() can fail to parse the input data, added a check to avoid setup the recurrence pattern in that case. This should only happen when input data is incorrect.
As described in [MS-OXCICAL] Section 2.1.3.11.20.4 by using
access CLASS iCal field.
Although Outlook does not support confidential level, it is properly
exported and imported.