DocumentSHA1EmailHeaderHash Property

[DataMemberAttribute]
public string SHA1EmailHeaderHash { get; set; }

Property Value

The email header hash source is the concatenated message EmailSentTime date (e.g., Outlook 'ClientSubmitTime' or MIME 'Date' field), subject, Sender name and email address, all converted to all lower case and all white space removed before hashing.

The message EmailSentTime is formatted as MM-dd-yyyy HH:mm:ss (in UTC if date is UTC). If EmailSentTime does not exist, and the email is an Microsoft Outlook Message object, then the Exchange property PidTagLastModificationTime (UTC) is used; otherwise, it is omitted from hash.

If the email is an Microsoft Outlook Appointment and Meeting object, then the PidLidAppointmentStartWhole and PidLidAppointmentEndWhole Exchange properties are used in place of EmailSentTime

Reference