Hello: I'm afraid that with the info you have provided is not possible at all even to try to diagnose your issue.
Could you plese share which is the configuration on your Zentyal server? Which is the domain that you can't receive mails from?
Does /var/log/mail.log or /var/log/mail.err show any message related to that domain? What are users from that domain receiving when they try to send a message to yours, does they receive any kind of error message? If so, which one, whatr does such email tells those users?
Topic: Cannot receive emails from a particular domain (Read 1555 times)