All email that are deleted will automatically go to your Trash Bin. The default of your Trash Bin is set to keep your deleted emails in there. There are a couple of ways to empty your trash of those unwanted emails.
You can select to delete these emails manually or setting your options to permanently deleting them for you.
Manually
Click on your Trash Bin. You will be able to identify it by seeing a Trash can image. It is located on the left hand side of the page.
Once you are redirected into the Trash window you will see all the emails that you have deleted.
At this point you can right click on the email that you wish to permanently delete. You then get a pop up window that lists the different options that can be done with this email. In this scenario; since you want to delete it, you will scroll down to the very last option and click on delete.
Your email has been permanently deleted. I would not highly recommend this option simply because if you have a lot of emails that you wish to permanent delete, this can be a long and tedious process.
Another manual process is clicking on the emails that you wish to permanently delete. You will see a green check mark pop up next to the email that will be deleted.
On the upper center part of your window you will see a trash can. Click on that. Your emails have been permanently deleted.
If you found these two manual ways long and tedious and prefer that your deleted emails be automatically deleted then you will have to setup your options to do it.
Automatic Options
Click on your Options button located on the far upper left hand side of the page (in the left side bar in Traditional Mode). You will be able to identify it by seeing an image of two tools (screw diver and wrench).
You will be redirected to Options for Dynamic Mail window. Click on Edit Options for: Choose Application:
A drop down will appear and you will select the Mail option.
Click on Login Tasks.
Once you click the Login Task Option you will see this:
If you look closely at this snapshot you will see that there is a check next to "", you would need to check this box because your default will have it blank.
You will then go to and click on "Purge Trash how often:". Here you will select your personal preferences. As you can see I selected Every Login.
Once you have selected your option click on your Save Options tab. This is found at the bottom of the page..