The e-mail priority indicates the importance of an e-mail. If you are using Microsoft Outlook, then a high priority e-mail has a red exclamation sign beside the message and a low priority has a blue downward- facing arrow. If an e-mail has a normal priority, then nothing is used to indicate the message importance. Use the following syntax to assign a priority to an e-mail:
MailObj.Priority = MailPriority.High
You also can use Normal and Low priority enumerations of the MailPriority object.