I have bought a domain name and some email hosting from a company (PurpleCloud).
I want to get my email hosting from another company. (Fastmail). I don't care who I register my domain with. (it's a .co.uk if that makes a difference.)
What do I need to do to achieve this? Do I buy the email hosting and use some control panel at the new provider? Or is there a combination of to-and-fro between different panels at both providers?