I am not sure if you are trying to exclude the sent-mail folder or what.. if you are just pulling out the phrase 'sent-mail' (which will pull it out of even recieved mail) then this will work:
echo $HOME/Mail/* | perl -e 'while(<>){$_=~ s/sent-mail//;if($_){print}}'

if you just want the received mail, then you are better off with this:

echo $HOME/Mail/received | perl -e 'print <>'
-p