Good morning to all, I write from Peru

Working with enough time and Zimbra have no problems, but this
Last week I touched install Zimbra in a company, which has a
and publishes a single IP router, when an email arrives with the router sends
to the mail server and goes. Today I got to Zimbra in centos
And the 4.7 version of Zimbra is 4.5.10 for Red Hat, but it soon
install in centos and there were no problems. Now the problem due to
network structure, leaving the post without a problem and comes to the
but at least mailboxes hotmail by the way, but when no reply
comes to nothing. Someone knows why? perhaps in this situation
ip one that is in the router to have to configure Zimbra
otherwise special? I hope someone can help me and it is almost certain
that this case may also serve others. Thank you and greetings from