Zimbra and Apache Integration

[tonnuchimse]

Hello,
I'm installing Apache and Zimbra on the same server.
Apache is using port 80 and is used to out website, port 443 is disable
Zimbra is using port 8082 and 443 for webmail.
At the first time, to redirect http webmail to Zimbra, I configure Apache to proxy and forward request to Zimbra via port 8082.
Then I enable SSL Mode in Apache by command

zmtlsctl https

Now I can access secure webmail via https://webmail.domain.com
But I want to force URL from http://webmail.domain.com redirect to https://webmail.domain.com
So how can I configure in Apache to redirect from http of Apache to https of Zimbra.
Thank you very much