Nginx reverse proxy to Exchange 2010/2013

nginx.conf

server {
        listen 80;
        #listen [::]:80;
        server_name mail.gwtest.us autodiscover.gwtest.us;
        return 301 https://$host$request_uri;
}

server {
        listen 443;
        #listen [::]:443 ipv6only=on;
        ssl                     on;
        ssl_certificate         /etc/ssl/nginx/mail.gwtest.us.crt;
        ssl_certificate_key     /etc/ssl/nginx/mail.gwtest.us.open.key;
        ssl_session_timeout     5m;

        server_name mail.gwtest.us;

        location / {
                return 301 https://mail.gwtest.us/owa;
        }

        proxy_http_version      1.1;
        proxy_read_timeout      360;
        proxy_pass_header       Date;
        proxy_pass_header       Server;
        proxy_pass_header       Authorization;

        proxy_set_header        Accept-Encoding "";
        proxy_set_header        Host $host;
        proxy_set_header        X-Real-IP $remote_addr;
        proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;

        more_set_input_headers 'Authorization: $http_authorization';
        more_set_headers -s 401 'WWW-Authenticate: Basic realm="exch1.test.local"';

        location ~* ^/owa { proxy_pass https://exch1.test.local; }
        location ~* ^/Microsoft-Server-ActiveSync { proxy_pass https://exch1.test.local; }
        location ~* ^/ecp { proxy_pass https://exch1.test.local; }
        location ~* ^/rpc { proxy_pass https://exch1.test.local; }
        #location ~* ^/mailarchiver { proxy_pass https://mailarchiver.local; }

        error_log /var/log/nginx/owa-ssl-error.log;
        access_log /var/log/nginx/owa-ssl-access.log;
}