Thank you all for the replies. It's obvious to me that this is technically a leap too far for me as although I am reasonably tech savvy, that does not stretch to this.
As an aside, I came to this as a way to solve the constant price rises that my host (one.com) keeps imposing. The latest is a limit on each email address with a £2 a month per account that goes over the limit.
I'm going to look at other hosts that support multiple email (as that's all I use), or I might just use it as a redirect to a gmail for example.
Once again, many thanks for all the replies.