I am using item.Restrict("[EMAIL1ADDRESS] = '"+email+"' AND [FIRSTNAME]
= '"+fName+"' AND [LASTNAME] = '"+lName+"'");
and it works fine when using Outlook in English, but in German it seems
be an issue:
Message: Die Eigenschaft "EMAIL1ADDRESS],[FIRSTNAME],[LASTNAME" ist
nicht bekannt.

I guess this means that this feature does not exist.

Any ideas?