We have done this with code but unfortunately it requires Full Trust to call Print programmatically. Another option is using digital signatures since InfoPath include image generation for them. That doesn't require Full Trust but will require code to programmatically sign the form and extract the image and attach it to e-mail. Also, your users will have to have a digital signature, so you will have to install a certificate authority to grant them. All quite doable though ... let us know if you would like to buy some code to do this. It took us probably 15-20 hours to get it working well ...
Patrick Halstead [InfoPath MVP]
InfoPathDev
Patrick Halstead
Project Manager at Qdabra