I would like to see the ability to password protect mailwasher.
The reason being my e-mail is password protected in outlook but when you use mailwasher it bypass your password so that anyone can read your e-mail.

You can opt to put your password in everytime MW checks mail by:
Tools > Accounts > Properties > Incoming Mail > Untick "Remember password".

yeah but that doesn't stop people viewing e-mails that mailwasher has already download.

What I'm thinking of is been asked for a password every time you try to open mailwasher or read an e-mail. Just so that your the only one that can see the e-mails.

You can set Mailwasher to only run for one user (you) then log off when you are away from the computer and someone else logging in would have no access to your desktop at all.

I keep my screen saver set to activate after 15 mins. of no activity and require a password to reopen. This prevents anyone from viewing or running anything and still allows MWP to check mail in the background. Note you do still hear the Mail Notification Sound when new legit mail arrives.