I deployed ZCS 5.0 GA into production last Tuesday. All is OK, and running smoothly. I can able to send/receive mail outside and inside my network. The only problem is that I cannot access the webmail outside our network (hostname.domain.com) i.e. Internet Cafe. I can access when use both local IP and hostname.domain.com inside our network. I do not have problem like this on my old server using postfix with clamav, spamassassin. Do you have any ideas what might be the problem is?