Email from hosted domain - help

[#1]

Hi
I currently have a website hosted and working with plus  say  www.ownwebsite.co.uk
I am trying to get an email address to work for this website    say  sales@ownwebsite.co.uk
I have 2 computers in house - i only want one to receive this mail
Can i set up a seperate mailbox for this mail only  say myplusname+ownwebsite
When I try this mail is delivered to my default plus address on my main computer
Can anyone help ?
thanks in hope

[#2]

Assuming you don't have email addressed to 'sales@myplusname', which seems unlikely from what you say, then you need to set up a mailbox called 'sales'.  You can collect from there by logging in as myplusname+sales.
Email to 'sales@myplusname' and 'sales@ownwebsite.co.uk' all gets delivered to mailbox 'sale'

[#3]

what type of hosting have you got ?
The settings vary from control panel to control panel
MArk