Have come across a scenario where using Outlook Spy I can see that my msg has the above said property. But once i export the pst and try to extract this message, this property does not exist in the expecte location i.e. 0x0001 index and offset 0x0040. However in outlook spy i see a tag num of 0x80B00040 and sure enough when I look at the property mappings i see in tag 0x80B0 i.e. this value. My question is that where does this tag value come from ? I do not find any references to it here http://msdn.microsoft.com/en-us/library/ee237112(v=exchg.80).aspx ?
Can someone also explain the relation between named property and tags ?