I am not sure which certificates are causing your headaches?

Virtual Appliance (9443) of SMG services (443)?

Neither.

The ssl part of the smtp interface configuration.

Well, so it is not VA 

I use the same settings for server and smtp settings.

Here are my settings - In my case I work with Letsencrypt. So I do not have a chain file and I do not have to provide a pass phrase. 

Can't use Letsencrypt. Port 80 is locked and I can't make the ACME work with port 443.

That's why I used an internal signed certificate. But, even when I used a commercial certificate from a different machine, the error was the same.

If the place holder info of the certificate and key have something there, the ssl error appears on the smtp.log and it get errors when communicating with external servers.

Letsencrypt was just an example - so even Letsencrypt will work ..

So if you use a certificate from another machine, then it is a wildcard certificate I assume, right?

(Internal created, self signed certificates will not really work with 'real' internet traffic because self signed certificates will not be accepted)

Nope, no wildcard, I understand that it shouldn't work, but the error is the odd part, because the old smg was working with an internal certificate.

 jr_albuquerque  Now I think I understand because I have checked the document you used for certificate generation (KM000007221).

Please, check your directories! See my screenshot! Search for vaserver.crt - this will be the right directory to store your certs. In my case it is /vastorage/conf/certs. But there are slight differences from va version to version. However I assume it is a subdirectory in /vastorage - not around /opt ...

Thanks Diethmar,

It worked!!

I've found that also google wasn't enjoying the tls without certificates on some servers.

Now everything is working fine, TLS1.2 and all.

Some work must be done on the documentation.

Yes, we know. And we requested it several times.