nlanas wrote:external emails are not arriving
You're not actually giving much useful information with which someone might be able to h help. What steps have you taken to diagnose your problem and to check your ZCS server is set-up correctly with all the required pre-requisites?
What do you mean by "not working on other ISP"? What exactly has changed in your set-up? Give a bit more descriptive posts and we may be give you some advice, you should also do some research on the forums to try and figure out your problem for yourself.