When I moved from AOL to ADSL24 that was the time I realised about using the ISP's own email service was a problem. Luckily AOL mail became free so had plenty of time to change to Gmail, Live mail etc. Anything but the ISP's own. On moving, both ADSL 24 and then to PlusNet, I was always kept well informed when I would need to change the router settings over to the new ISP, so had minimum disruption both times.
Huawei P10 review