Multiple email accounts best practice


New Email
Hi, I am trying to make my life simpler by applying rules to my emails. I have approx 10 email addresses i need to work with ( i am running various freelance businesses all in need of different emails and ability to reply from different emails).

First I tried google as i liked the ease of applying rules - i connected 5 accounts and realised that 5 is the limit so i have now unconnected them again.

then i tried outlook live - i connected most of my accounts but it seems convoluted and difficult to use and the connected accounts are not reflected in the same way on the iphone app.

I am about to disconnect the accounts from outlook live but have realised this will delete the emails from each account and i would like to keep them for reference.

So my question is in 2 parts.

How can I keep all my emails and disconnect the accounts from outlook live

and what easy way is there to handle more than 5 multiple email accounts so i can apply rules and see them on a mac, web and iphone

thanks in advance,