Mail Help

There are several posts about this, but I am still confuses...

I have two e-mail accounts on my Mail app- a comcast and a Gmail.
The comcast e-mail allows me to delete a message on the phone but keep it on the server (I can still access it on my computer later).
This is what I want.

The Gmail, however, deletes it on the server when I delete it on the phone. I have tried going through settings into the "advanced" menu, but that's not working (from what I can gather, it's because I'm on an IMAP sever instead of POP.)

I would really like to be able to delete messages on my phone but access them later on my computer.

Any ideas?
Thanks!