I am having enormous problems with 2 existing ISPs whose POP3 servers keep going down - I need to change

My requirements are

upto 100 mail boxes
I don't need to transfer my domain - I'll set up a new domain
Easy configuration of each mail box for forwarding to at least 3 destinations
Away from office handling
proven track record of near 100% up time
24/7 support based on their premises ie not outsourced to India, Phillipines etc

Any suggestions

Thanks

Colin Northway