OutLook security automation using c#.NET ContactItem::userCertificate hi, I am Trying to automate the process of adding security certificate for users in outlook contacts. I use c#.NET to set the certificate using: ContactItem 's userCertificate property e.g. contact.userCertificate = "c:\...\xx.cer"; This seeems to be not working always. In the msdn documentation it is written that this property of `contactItem` class is depricated and is not intended for use in the code. I need a very reliable way of setting the user's certificate in outlook contacts programmatically . Please suggest me if there is a way of doing this. thanks, teja .