SSL_connect returned=1 errno=0 peeraddr= state=error: certificate verify failed (unable to get local issuer certificate)

We’ve done all the authentication settings, and we’re using port 25.
Has anyone experienced this SSL certificate error?

Can I be missing a certificate? Where?

It is a problem with the certificate on your mail server. A common issue is that it has a certificate for only one domain but a bunch of domains resolve to it.

Maybe google “smtp ssl cerftificate test” and find something like //email/testTo:

@pfaffman Can discourse use 25 port in smtp configuration using autenticated method? or is there some restriction??