Redirect http to https
This will allow initial connections over http, but always redirect them to https. If you just want to force authentication to occur over https, just use zmtlsctl mixed.
Edit Login.jps
This prevents the server from redirecting back to http if the initial connection is http.
In the file /opt/zimbra/tomcat/webapps/zimbra/public/Login.jsp, comment out this statement:
qs = emptyQs? "?initMode=" + currentProto: qs + "&initMode=" + currentProto;
In other words, make it look like this:
//qs = emptyQs? "?initMode=" + currentProto: qs + "&initMode=" + //currentProto;
Network Edition Users: Be aware that each node of the cluster needs to have this change applied.
Set mixed mode
This configures the server to accept both http and https connections.
su - zimbra zmtlsctl mixed tomcat restart