The POP distinction doesn't apply to those of us using the "keep mail on server" option. As said in the first reply,everything stays in the inbox until full and it can't take in more mail. Trash folders are usually emptied at the provider's discretion. The POP options include leaving the mail for a specified number of days or until a specified action is taken. Annoyingly, in the case of one email program, the instruction to delete from the server if I delete a message was applied if I either deleted it or moved it to another folder (other than the inbox). A person could accidentally delete messages this way.