Hi dodge55,
Yes it is totally possible to use ports other than 443. Use TCP API's to connect to whatever port you wish and set the resulting FD with wolfSSL_set_fd(ssl, sockfd);. For examples you can find some simpler examples in our github wolfssl-examples repo like this simple client here: https://github.com/wolfSSL/wolfssl-exam … ient-tls.c
There are two options WRT certs you can either use pre-shared keys to avoid sending any certs but this requires both client and server to share a common key in advance E.G. you need to provision all clients and servers where every server has keys for every client it expects to connect.
The other option to not send certificates would be to use a cipher suite that typically uses certs but disable all cert verification all the time. This is not recommended. There would still be a key exchange happening in this case though and if you don't send certs it's likely the peer is still going to want them EG the servers handling the emails. I don't think you can get around the certificates requirement.
Warm Regards,
K