My ISP (plusnet) allows you to do just this.
The ISP firewall is turned off by default when you sign up though.
That moves them onto my list of ISPs to recommend. The only other ISP on that list is A&A Internet.
They also allow you to have port 25 open, and will give you a fixed IP address for £5.
@Velocio started
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My ISP (plusnet) allows you to do just this.
The ISP firewall is turned off by default when you sign up though.