I would be more inclined to use an independent email system then what the ISP offers. ISP’s come and go and people move, if you use say Yahoo, no matter where you go, you email address follows. If I were in your shoes, I would convert to Yahoo and leave it at that. Nothing says the conversion would happen overnight, but tell everyone your new email address and when you respond to any messages, make sure the return address is your Yahoo. After sometime you won’t be receiving any in your old email accounts.