Anyone know what this error code refers to? It is being created by a Send Mail error. 1636 is right next to a lot of errors relating to SSL certificates, so I suspect that it is something to do with SSL but it's not listed in the codes online.
Perhaps this information helps: Claris Community (English)
Yes, it fits with what I'm seeing. The email connection works from the client but not when running on the server.
I found a lot of similar threads when I searched for "Send Mail error 1636".
Is the outgoing SMTP server an Exchange or anything else?
It's an SMTP server running from a shared hosting environment. I suspect that there is a domain mismatch with the SSL certificate on the FileMaker server.
If this is true, then FMS19 probably incorrectly checks the certificate of its own server instead of the certificate of the SMTP server. That would be an extremely stupid bug.