The Subject property sets filtering on a message's subject. Read/write.
objMessageFilter.Subject
The Subject property is the default property of a MessageFilter object, meaning that objMessageFilter is syntactically equivalent to objMessageFilter.Subject in Microsoft® Visual Basic® code.
String
The Subject property specifies that the message filter should pass only messages having a Subject that contains the string in this Subject property as a substring.
The Subject property corresponds to the MAPI property PR_SUBJECT.