how to send to multiple recipients but they can only see themselves in the recipient field

[7omato]

when I use the message.SetHeader("To", "aa","bb") then "aa","bb" will be on the recipient field
when I use the message.SetHeader("Bcc", "bb") & message.SetHeader("To", "aa" ) then "bb" can still see "aa" as recipient thougth "aa" can't see "bb" now
when I use the message.SetHeader("Bcc", "aa","bb") only then the recipient field is empty , and it's weird

so , how can I use the method to send mail to "ab","bb" in one mail and they can see their own name on the recipient field ?
because I'm going to cc to another address so that I can't spilt the recipients to send themselves each .
thank you for your answer

[wneessen]

Create a new message for each recipient.