what sort of things would you expect to be regulated?
all the major isp's treat email as a free addon so is not even a paid for service.
I have never heard of a deadlock with an isp over email.
One of the problems is the fact that ISPs claim it is not a paid for service and therefore there is no "contract" between them and the user.This allows them amongst other things to impose any conditions they like on email use. For example they can insist that they can read any user emails, close the email account whenever they want , refuse to correct any problems etc.
I have reached a deadlock situation with a major ISP where they removed a facility with no notification. This caused emails to be deleted without warning. Their system still indicated that the facility was still there and gave no failure message when used. They confirmed that this was the case but as email was a free add on they had no obligation to fix the issue.
What needs to be regulated amongst other things is that a) any email system provided as part of internet service provision is a contractual commitment and cannot be treated as an alleged free add on. b) there should be a commited level of service including things like privacy, reliability and security and c) any email account should not be arbritarily cancelled and any associated address should be allowed to be transfered to anothe provider.
I would suspect that mobile phone services have regulations that could be applied to email provision.