Removing an email account does not delete it forever. It's still accessible from other devices. Alternative options include disabling the account or hiding new email alerts. This article explains how ...
To delete all voicemails on your iPhone at once, you'll have to select them one by one. You can also export the voicemails if you want to save them.
It's easy to delete your frequently visited sites on an iPhone in Safari. Here's what you need to know to do it.