Outlook 2007 Can’t “Send to mail recipient”

Hi all,
I can’t use the function “Send to mail recipient” using Windows XP Pro SP2 and Outlook 2007. I know that some post suggest to make Outlook as my default mail client and it’s done nothing good on my side. I’ve tried to set Outlook Express as the default and the option works, but as soon as I put Outlook 2007 the function simply doesn’t work. I’ve also tried the “regsvr32 sendmail.dll” command without success.

Thanks for your time !