using smrsh to capture mail stream to file

i have a script setup as an alias that starts off with:
#!/bin/ash
extension=`date +%s`.CF.wri
cat $1 > /home/cree/incoming.$extension

Is this a proper use of cat , can I just use
$1 > /home/cree/incoming.$extension ?

I have work that needs to process the file
/home/cree/incoming.$extension
and cat sometimes messes things up by not dealing properly with html
code and long lines when the email is larger than 6K