Email that does not clog my phone

Hi everyone,

I use several devices Lenovo K5, Samsung J7, Lenovo Yoga tablet, Huawei M3 Tablet.
I have for some time now used an app Bluemail (which I like) but...and there is one big problem I do not know how to solve which probably applies to all mail apps. When I delete a mail it goes to a trash folder, or is it is spam it goes to a spam folder and I then have to delete them all over again.
So the question is does anyone know how to make "delete" work the first time and every time? Not to ask me silly questions like "are you sure" or " this will permanently" delete this file"... if I press delete it is because I want to get rid of it for ever! Not clog up up another portion of the memory!
Cheers
Tim

Welcome to Android Central! What email provider are you using? If the email app is using an IMAP server, it won't build up in the phone's storage, because the email app would only be syncing the email headers, not the whole emails -- i.e., all of those emails don't physically save to the phone's storage. They're kept on the email provider's server. POP3 is a different story, but that's an older protocol which doesn't allow folder syncing, so IMAP is generally preferred. See here for more detail: http://www.pop2imap.com/