The answer to this one is “Yes, and No”. Yes, you should stick with your current IT support company for email, networking and other services they may provide (including webdisk, DNS routing and intranet) – but “No”, you do not have to stick with them for programming your new website.
While your IT support company may be very good at hardware and servers, they may not specialise in website development. When deciding who you would like to build the “back end” of your website, ask yourself if websites are the core business of the company you are considering, or if it is marketed as an additional service.
We always recommend you use a specialist company for your website needs rather than a “jack of all trades”.
Finally, when it comes to publishing your site, PSD to Final can work with your IT support team to update your domain name server (DNS) settings – allowing website traffic to be routed correctly, without affecting any other service (email, exchange, webdisk, intranet, etc).