Hi ,
You have to wirte the filter yourself, please refer to this link for the syntax.
http://www.outlookcode.com/news.aspx?id=30and we could also use DASL in Items.Restract method To use DASL syntax in Items.Restrict method by prefix the DASL search string with @SQL=.
Here's the offical example of serarch subject field:
http://msdn.microsoft.com/en-us/library/bb220369.aspxThanks
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