Member name	Value	Description
DateReceived	15	Specifies the date and time that the message was received on the server.
DisplayTo	17	Specifies the names of the primary recipients of the message.
Importance	18	Specifies the importance of the message, as determined by the sender.
MessageClass	19	Specifies the message class of this e-mail message.
Subject	20	Specifies the subject of the e-mail message or the subject of the flag as it would appear in a task list.
Read	21	Specifies whether the message has been read.
To	22	Specifies the list of recipients
Cc	23	Specifies the list of secondary recipients.
From	24	Specifies the e-mail address of the message sender.
ReplyTo	25	Specifies the e-mail address to which replies will be addressed by default.
AllDayEvent	26	Specifies whether the calendar item is an all-day event.
Categories	27	Specifies the user-selected categories for this message.
Category	28	Specifies the category for this e-mail item.
DtStamp	29	Specifies the date and time that the calendar item was created.
EndTime	30	Specifies the date and time that the meeting ends.
InstanceType	31	Specifies the type of calendar item.
BusyStatus	32	Specifies the intended busy status for the meeting request.
Location	33	Specifies the location for the calendar item.
MeetingRequest	34	Specifies a meeting request accompanying an e-mail message.
Organizer	35	Specifies the e-mail alias of the meeting organizer.
RecurrenceId	36	Specifies a specific instance of a recurring calendar item.
Reminder	37	Specifies the number of seconds prior to the calendar item's start time that a reminder is displayed.
ResponseRequested	38	Specifies whether the originator of the meeting has requested a response.
Recurrences	39	Specifies a collection of Recurrence elements.
Recurrence	40	Specifies a collection of Recurrence elements that describe when and how often this meeting recurs.
Type	41	Specifies the recurrence type of the recurring meeting.
Until	42	Specifies the end time of a series of recurrence meetings.
Occurrences	43	Specifies the number of occurrences before the series of recurring meeting ends.
Interval	44	Specifies the interval between recurrences of the recurring meeting.
DayOfWeek	45	Specifies the day of the week of the recurring meeting.
DayOfMonth	46	Specifies the day of the month of the recurring meeting.
WeekOfMonth	47	Specifies the week of the month of the recurring meeting.
MonthOfYear	48	Specifies the month of the year of the recurring meeting.
StartTime	49	Specifies the date and time that the meeting starts.
Sensitivity	50	Specifies the confidentiality level of the meeting request.
TimeZone	51	Specifies the time zone specified when the calendar item was created.
GlobalObjId	52	Specifies a 76-digit hexadecimal ID generated by the client for the meeting request.
ThreadTopic	53	Specifies the topic used in conversation reading.
InternetCPID	57	Specifies the original code page ID from the MIME message.
Flag	58	Specifies the flag associated with the item, along with the item's current status.
Status	59	Specifies the current status of the flag.
ContentClass	60	Specifies the content class of the data.
FlagType	61	Specifies the type of the flag.
CompleteTime	62	Specifies the time at which the flagged item was marked as finished.
DisallowNewTimeProposal	63	Specifies whether recipients can propose a new meeting time.

Reference

Aspose.Email.Clients.ActiveSync.TransportLayer Namespace