
At present I am still using the Filemaker supplied certificate. However, it is important to me that the connection is properly encrypted because the information is sensitive. I don’t really mind this because I am only sharing the database with a few select individuals and I can reassure them and persuade them to manually override the warnings.

I am aware that Filemaker does not recognise Certbot as an authorised CA and as such comes up with warnings (just as it does with its own development certificate). I recently managed to obtain certificates for my MacMini running Filemaker Server 15.0.3 within my LAN using a dyndns Host Name.
