Node JS express-http-proxy: Unable to load first c

问题:

I have a node js server on the local lan that loads 3 public sites based on req.hostname:

app.get('/*',function(req,res){
    console.dir(req.hostname);
    console.dir(req.path);
    var hostPath = '';
    var pagePath = '';
    if (req.path === '/') { pagePath = '/index' } else { pagePath = req.path }

    switch(req.hostname){
        case 'dom-1.com':
        case 'www.dom-1.com':
        hostPath = 'pages/dom-1';
        break;
        case 'dom-2.com':
        case 'www.dom-2.com':
        hostPath = 'pages/dom-2';
        break;  
        case 'dom-3.com':
        case 'www.dom-3.com':
        hostPath = 'pages/dom-3';
        break;
    }
    res.render(hostPath + pagePath);
});

above this code I have the following with which I am trying to also serve (via port 443) my mail server on a the lan via proxy:

app.use('/mail/', proxy('https://192.168.0.87',{
    https: true
}));

but I get when loading https://mail.email.com/mail in a browser from outside the local lan:

Error: unable to verify the first certificate
at TLSSocket.<anonymous> (_tls_wrap.js:1116:38)
at emitNone (events.js:106:13)
at TLSSocket.emit (events.js:208:7)
at TLSSocket._finishInit (_tls_wrap.js:643:8)
at TLSWrap.ssl.onhandshakedone (_tls_wrap.js:473:38)

We have gone through the steps to verify the certs are all the same on this server and the mail server

We tried doing

require('https').globalAgent.options.ca = require('ssl-root-cas/latest').create();

but this just breaks things, saying https.createServer is not a function (down further in the code)

If anyone has some suggestions for us, that would be awesome!