mail from gmail only....but sent from hotmail account.

i have set up 2 hotmails account and just added a gmail account to mail on Lion couple days ago.

i just found out that even though i send email thru my hotmail account. the receiver sees my gmail address on their mail.

why is it doing this?

the preference is set up correctly it will send email from selected mailbox.

and whenever i look at the sent box it shows the correct hotmail address.....weird...